Kalashnikov's father was deported when Kalashnikov was still a boy. In his youth Kalashnikov wrote poetry, and he was expected to become a poet. He went on to write six books and continued to write poetry all his life.Kalashnikov was conscripted into the Red Army in 1938, and became a tank driver-mechanic, achieving the rank of senior sergeant (tank commander) serving on the T-34s of the 24th Tank Regiment, 12th Tank Division stationed in Stryi before the regiment retreated after the failed counterattack at Brody, June 1941. He was wounded in combat during the defence of Bryansk, October 1941, and released for six months recuperation due to illness. While in the hospital, he overheard some soldiers complaining about the Soviet rifles of the time.

He also had bad experiences with the standard infantry weapons at the time, so he was inspired to start constructing a new rifle for the Soviet military. During this time Kalashnikov began designing a submachine gun.

Although his first submachine gun design was not accepted to service, his talent as a designer was noticed. From 1942 onwards Kalashnikov was assigned to the Central Scientific-developmental Firing Range for Rifle Firearms of the Chief Artillery Directorate of RKKA. Later in life he claimed that the priority of simplicity and dependability in his designs was influenced by principles he had gained from reading of Russian literature and the Bible.

In 1944, he designed a gas-operated carbine for the new 7.62x39 mm cartridge; this weapon, influenced by the StG 44 assault rifle, lost out to the new Simonov carbine which would be eventually adopted as the SKS; but it became a basis for his entry in an assault rifle competition in 1946.His winning entry, the "Mikhtim" (so named by taking the first letters of his name and patronymic Mikhail Timofeyevich) became the prototype for the development of a family of prototype rifles.

This process culminated in 1947, when he designed the AK-47 (standing for Avtomat Kalashnikova model 1947). In 1956, the AK-47 assault rifle became the Soviet Army's standard issue rifle and went on to become Kalashnikov's most famous invention.

Since 1949, Mikhail Kalashnikov has lived and worked in Izhevsk, Udmurtia. He holds an advanced degree of Doctor of Technical Sciences.

After WWII, as General Designer of small arms for the Soviet Army, his design subordinates included the Germans Hugo Schmeisser, designer of the StG-44, and Werner Grüner (of MG 42 fame) who was a pioneer in sheet metal embossing technology in the 1950s.

Over the course of his career he evolved the basic design into a weapons family. The AKM ("Avtomat Kalashnikov Modernizirovanniy" - Automatic Kalashnikov Modernized) first appeared in 1963, which was lighter and cheaper to manufacture due to the use of a stamped steel receiver (in place of the AK47's milled steel receiver), and contained detail improvements such as a re-shaped stock and muzzle compensator. From the AKM he developed a squad automatic weapon variant, known as the RPK (Ruchnoi pulemyot Kalashnikova - Kalashnikov light machine gun), and also the PK (Pulemyot Kalashnikova - Kalashnikov machine gun), which used the more powerful 7.62×54R of the Mosin-Nagant rifle. The PK series is a general purpose machine gun, which is cartridge belt-fed, not magazine-fed, as it is intended to fill the heavy tripod-mounted sustained fire role as well as the light, bipod-mounted role. The common characteristics of his weapons are the simple, elegant engineering and their ruggedness and ease of maintenance in all operating conditions.

Despite estimates of some 100 million AK-47 assault rifles circulating, General Kalashnikov claims he has not profited and that he only receives a state pension.He does however own 13% of a German company Marken Marketing International (MMI), based in Solingen, that revamps trademarks and produces merchandise carrying the Kalashnikov name, such as vodka, umbrellas and knives. One of the items is a knife named for the AK-74.

Kalashnikov told Reuters Television, "I've always wanted to improve and expand on the good name of my weapon by doing good things."

The legacy of Kalashnikov's rifles as the most popular assault rifles has prompted him to state that

"When I see Bin Laden with his AK-47, I got nervous. But what can I do, terrorists aren't fools: they too chose the most reliable guns."

"I'm proud of my invention, but I'm sad that it is used by terrorists," he said on a visit to Germany, adding: "I would prefer to have invented a machine that people could use and that would help farmers with their work ... for example a lawnmower."(2002)

Mikhail Kalashnikov was twice named Hero of Socialist Labor. In 1998, he was awarded an Order of Saint Andrew the Protoclete (orden Svyatogo Andreya Pervozvannogo).

On 10 November 2009 (his 90th birthday), Kalashnikov was named a "Hero of the Russian Federation" and presented with a medal by President Dmitry Medvedev who lauded him for creating "the brand every Russian is proud of."