Rothbard was born to David and Rae Rothbard, who raised their Jewish family in the Bronx. His father worked as a chemist and immigrated to the US from Poland, while his mother came from Russia. "I grew up in a Communist culture," he recalled. He attended Columbia University, where he was awarded a Bachelor of Arts degree in mathematics and economics in 1945 and a Master of Arts degree in 1946. He earned a Doctor of Philosophy degree in economics in 1956 at Columbia under Joseph Dorfman.

During the early 1950s, he studied under the Austrian economist Ludwig von Mises at his seminars at New York University and was greatly influenced by Mises' book Human Action. In the 1950s and 1960s he worked for the liberal William Volker Fund on a book project that resulted in Man, Economy, and State, published in 1962. From 1963 to 1985, he taught at Polytechnic Institute of New York University in Brooklyn, New York. From 1986 until his death he was a distinguished professor at the University of Nevada, Las Vegas. Rothbard founded the Center for Libertarian Studies in 1976 and the Journal of Libertarian Studies in 1977. He was associated with the 1982 creation of the Ludwig von Mises Institute and later was its academic vice president. In 1987 he started the scholarly Review of Austrian Economics, now called the Quarterly Journal of Austrian Economics.

In 1953 in New York City he married JoAnn Schumacher, whom he called the "indispensable framework" for his life and work. He died in 1995 in Manhattan of a heart attack. The New York Times obituary called Rothbard "an economist and social philosopher who fiercely defended individual freedom against government intervention."

The Austrian School attempts to discover axioms of human action (called "praxeology" in the Austrian tradition). It supports free market economics and criticizes command economies. Influential advocates were Eugen von Böhm-Bawerk, Friedrich Hayek, and Ludwig von Mises. Rothbard argued that the entire Austrian economic theory is the working out of the logical implications of the fact that humans engage in purposeful action. In working out these axioms he came to the position that a monopoly price could not exist on the free market. He also anticipated much of the “rational expectations” viewpoint in economics.

In accordance with his free market views Rothbard argued that individual protection and national defense also should be offered on the market, rather than supplied by government’s coercive monopoly. Rothbard was an ardent critic of Keynesian economic thought as well as the utilitarian theory of philosopher Jeremy Bentham.

In Man, Economy, and State Rothbard divides the various kinds of state intervention in three categories: "autistic intervention", which is interference with private non-exchange activities; "binary intervention", which is forced exchange between individuals and the state; and "triangular intervention", which is state-mandated exchange between individuals. According to Sanford Ikeda, Rothbard's typology "eliminates the gaps and inconsistencies that appear in Mises's original formulation."

Rothbard also was knowledgeable in history and political philosophy. Rothbard's books, such as Man, Economy, and State, Power and Market, The Ethics of Liberty, and For a New Liberty, are considered by some to be classics of natural law and libertarian thought, combining libertarian natural rights philosophy, anti-government anarchism and a free market perspective in analyzing a range of contemporary social and economic issues. He also possessed extensive knowledge of the history of economic thought, studying the pre-Adam Smith free market economic schools, such as the Scholastics and the Physiocrats and discussed them in his unfinished, multi-volume work, An Austrian Perspective on the History of Economic Thought.

Rothbard writes in Power and Market that the role of the economist in a free market is limited, but the role and power of the economist in a government which continually intervenes in the market expands, as the interventions trigger problems which require further diagnosis and the need for further policy recommendations. Rothbard argues that this simple self-interest prejudices the views of many economists in favor of increased government intervention.

Rothbard also created "Rothbard's law" that "people tend to specialize in what they are worst at. Henry George, for example, is great on everything but land, so therefore he writes about land 90% of the time. Friedman is great except on money, so he concentrates on money."

Rothbard "combined the laissez-faire economics of his teacher Ludwig von Mises with the absolutist views of human rights and rejection of the state he had absorbed from studying the individualist American anarchists of the nineteenth century such as Lysander Spooner and Benjamin Tucker." He connected these to more modern views, writing: "There is, in the body of thought known as 'Austrian economics', a scientific explanation of the workings of the free market (and of the consequences of government intervention in that market) which individualist anarchists could easily incorporate into their political and social Weltanschauung."

Rothbard opposed what he considered the overspecialization of the academy and sought to fuse the disciplines of economics, history, ethics, and political science to create a "science of liberty." Rothbard described the moral basis for his anarcho-capitalist position in two of his books: For a New Liberty, published in 1972, and The Ethics of Liberty, published in 1982. In his Power and Market (1970), Rothbard describes how a stateless economy might function.

Self-ownership

In The Ethics of Liberty, Rothbard asserts the right of total self-ownership, as the only principle compatible with a moral code that applies to every person—a "universal ethic"—and that it is a natural law by being what is naturally best for man. He believed that, as a result, individuals owned the fruits of their labor. Accordingly, each person had the right to exchange his property with others. He believed that if an individual mixes his labor with unowned land then he is the proper owner, and from that point on it is private property that may only exchange hands by trade or gift. He also argued that such land would tend not to remain unused unless it makes economic sense to not put it to use.

Egalitarianism

The title essay of Murray Rothbard’s 1974 book Egalitarianism as a Revolt Against Nature and Other Essays held that “Equality is not in the natural order of things, and the crusade to make everyone equal in every respect (except before the law) is certain to have disastrous consequences.” In it Rothbard wrote, “At the heart of the egalitarian left is the pathological belief that there is no structure of reality; that all the world is a tabula rasa that can be changed at any moment in any desired direction by the mere exercise of human will.” Rothbard also expressed his views that statists suppressed academic research on race in order to support their goal of using the state to enforce egalitarian goals.

In a 1963 article called the “Negro revolution” Rothbard wrote that “the Negro Revolution has some elements that a libertarian must favor, others that he must oppose. Thus, the libertarian opposes compulsory segregation and police brutality, but also opposes compulsory integration and such absurdities as ethnic quota systems in jobs.” According to Rothbard biographer Justin Raimondo, Rothbard considered Malcolm X to be a “great black leader” and Martin Luther King to be favored by whites because he “was the major restraining force on the developing Negro revolution.” Rothbard also compared U.S. President Lyndon Baines Johnson’s use of troops to crush urban rioters in 1968 after King’s assassination to Johnson’s use of American troops against the Vietnamese.

Children and rights

In the Ethics of Liberty Rothbard explores in terms of self-ownership and contract several contentious issues regarding children's rights. These include women's right to abortion, proscriptions on parents aggressing against children once they are born, and the issue of the state forcing parents to care for children, including those with severe health problems. He also holds children have the right to "run away" from parents and seek new guardians as soon as they are able to choose to do so. He suggested parents have the right to put a child out for adoption or even sell the rights to the child in a voluntary contract, which he feels is more humane than artificial governmental restriction of the number of children available to willing and often superior parents. He also discusses how the current juvenile justice system punishes children for making "adult" choices, removes children unnecessarily and against their will from parents, often putting them in uncaring and even brutal foster care or juvenile facilities.

Anarcho-capitalism

Rothbard began to consider himself a private property anarchist in the 1950s and later began to use "anarcho-capitalist". He wrote: "Capitalism is the fullest expression of anarchism, and anarchism is the fullest expression of capitalism." In his anarcho-capitalist model, a system of protection agencies compete in a free market and are voluntarily supported by consumers who choose to use their protective and judicial services. Anarcho-capitalism would mean the end of the state monopoly on force.

Rothbard was equally condemning of relationships he perceived between big business and big government. He cited many instances where business elites co-opted government's monopoly power so as to influence laws and regulatory policy in a manner benefiting them at the expense of their competitive rivals. He wrote in criticism of Ayn Rand's "misty devotion to the Big Businessman" that she: "is too committed emotionally to worship of the Big Businessman-as-Hero to concede that it is precisely Big Business that is largely responsible for the twentieth-century march into aggressive statism..." According to Rothbard, one example of such cronyism included grants of monopolistic privilege the railroads derived from sponsoring so-called conservation laws.

Free market money

See also Free banking and Gold standard

Rothbard believed the monopoly power of government over the issuance and distribution of money was inherently destructive and unethical. The belief derived from Ludwig von Mises and Friedrich Hayek's Austrian theory of the business cycle, which holds that undue credit expansion inevitably leads to a gross misallocation of capital resources, triggering unsustainable credit bubbles and, eventually, economic depressions. He therefore strongly opposed central banking and fractional reserve banking under a fiat money system, labeling it as "legalized counterfeiting" or a form of institutionalized embezzlement and therefore inherently fraudulent. He characterized the government-enforced prohibition on citizens using commodity currencies as legal tender a compulsory Ponzi scheme, a Ponzi scheme from which no citizen could escape.

He strongly advocated full reserve banking ("100 percent banking") and a voluntary, nongovernmental gold standard or, as a second best solution, free banking (which he also called "free market money").

In relation to the current central bank-managed fractional reserve fiat currency system, he stated the following:

Given this dismal monetary and banking situation, given a 39:1 pyramiding of checkable deposits and currency on top of gold, given a Fed unchecked and out of control, given a world of fiat moneys, how can we possibly return to a sound noninflationary market money? The objectives, after the discussion in this work, should be clear: (a) to return to a gold standard, a commodity standard unhampered by government intervention; (b) to abolish the Federal Reserve System and return to a system of free and competitive banking; (c) to separate the government from money; and (d) either to enforce 100 percent reserve banking on the commercial banks, or at least to arrive at a system where any bank, at the slightest hint of nonpayment of its demand liabilities, is forced quickly into bankruptcy and liquidation. While the outlawing of fractional reserve as fraud would be preferable if it could be enforced, the problems of enforcement, especially where banks can continually innovate in forms of credit, make free banking an attractive alternative.

Noninterventionism

Believing like Randolph Bourne that "war is the health of the state" Rothbard opposed aggressive foreign policy. He criticized imperialism and the rise of the American empire which needed war to sustain itself and to expand its global control. His dislike of U.S. imperialism even led him to eulogize and lament the CIA-assisted execution of Marxist revolutionary Che Guevara in 1967, proclaiming that "his enemy was our enemy". Rothbard believed that stopping new wars was necessary and knowledge of how government had seduced citizens into earlier wars was important. Two essays expanded on these views "War, Peace, and the State" and "The Anatomy of the State". Rothbard used insights of the elitism theorists Vilfredo Pareto, Gaetano Mosca, and Robert Michels to build a model of state personnel, goals, and ideology. In an obituary for historian Harry Elmer Barnes Rothbard explained why historical knowledge is important:

Our entry into World War II was the crucial act in foisting a permanent militarization upon the economy and society, in bringing to the country a permanent garrison state, an overweening military-industrial complex, a permanent system of conscription. It was the crucial act in creating a mixed economy run by Big Government, a system of state-monopoly capitalism run by the central government in collaboration with Big Business and Big Unionism.

Rothbard discussed his views on the principles of a libertarian foreign policy in a 1973 interview: "minimize State power as much as possible, down to zero, and isolationism is the full expression in foreign affairs of the domestic objective of whittling down State power." He further called for "abstinence from any kind of American military intervention and political and economic intervention." In For a New Liberty he writes: "In a purely libertarian world, therefore, there would be no 'foreign policy' because there would be no States, no governments with a monopoly of coercion over particular territorial areas."

In "War Guilt in the Middle East" Rothbard details Israel's "aggression against Middle East Arabs," confiscatory policies and its "refusal to let these refugees return and reclaim the property taken from them." Rothbard also criticized the “organized Anti-Anti-Semitism” that critics of the state of Israel have to suffer. Rothbard criticized as terrorism the actions of the United States, Israel, and any nation that "retaliates" against innocents because they cannot pinpoint actual perpetrators. He held that no retaliation that injures or kills innocent people is justified, writing "Anything else is an apologia for unremitting and unending mass murder."

As a young man, Rothbard considered himself part of the Old Right, an anti-statist and anti-interventionist branch of the U.S. Republican party. When interventionist cold warriors of the National Review, such as William F. Buckley, Jr., gained influence in the Republican party in the 1950s, Rothbard quit the party. After Rothbard died, Buckley wrote a bitter obituary in the National Review criticizing Rothbard's "defective judgement" and views on the Cold War.

During the late 1950s, Rothbard was an associate of Ayn Rand and her philosophy, Objectivism, along with other students of Ludwig von Mises, such as George Reisman. According to Rand biographer Jennifer Burns, Rothbard was introduced to both Aristotelian epistemology and the "whole field" of natural rights through his discussions with Rand, and, at one time, described Rand's novel, Atlas Shrugged, as "not merely the greatest novel ever written, it is one of the very greatest books ever written, fiction or nonfiction." Later, however, he left her circle and lampooned their relationship in his fictionalized play Mozart Was a Red.

In the late 1960s, Rothbard advocated an alliance with the New Left anti-war movement, on the grounds that the conservative movement had been completely subsumed by the statist establishment. However, Rothbard later criticized the New Left for supporting a "People's Republic" style draft. It was during this phase that he associated with Karl Hess and founded A Journal of Libertarian Thought with Leonard Liggio and George Resch, which existed from 1965 to 1968. From 1969 to 1984 he edited The Libertarian Forum, also initially with Hess (although Hess's involvement ended in 1971).

Rothbard criticized the "frenzied nihilism" of left-wing libertarians, but also criticized right-wing libertarians who were content to rely only on education to bring down the state; he believed that libertarians should adopt any non-immoral tactic available to them in order to bring about liberty.

During the 1970s and 1980s, Rothbard was active in the Libertarian Party. He was frequently involved in the party's internal politics. From 1978 to 1983, he was associated with the Libertarian Party Radical Caucus, allying himself with Justin Raimondo, Eric Garris and Williamson Evers. He opposed the "low tax liberalism" espoused by 1980 Libertarian Party presidential candidate Ed Clark and Cato Institute president Edward H Crane III. Rothbard split with the Radical Caucus at the 1983 national convention over cultural issues, and aligned himself with what he called the "rightwing populist" wing of the party, notably Lew Rockwell and Ron Paul, who ran for President on the Libertarian Party ticket in 1988 and in the 2008 Republican Party Primaries.

In 1989, Rothbard left the Libertarian Party and began building bridges to the post-Cold War anti-interventionist right, calling himself a paleolibertarian. He was the founding president of the conservative-libertarian John Randolph Club and supported the presidential campaign of Pat Buchanan in 1992, saying "with Pat Buchanan as our leader, we shall break the clock of social democracy." However, later he became disillusioned and said Buchanan developed too much faith in economic planning and centralized state power.

According to Lew Rockwell, Rothbard is considered the "dean of the Austrian School of economics, the founder of libertarianism, and an exemplar of the Old Right".