Megadeath formed when Metallica fired Dave Mustaine. He went to Los Angeles and started a new band with David Ellefson (bass) and Greg Handevidt (guitar) in 1983. Lee Rausch became the drummer, while Handevidt left the band. Later, Gar Samuelson replaced Rausch and Chris Poland (guitar) joined the band.
Megadeath released " Killing Is My Business... and Business Is Good!" as debut album in 1985. Their second one, " Peace Sells... but Who's Buying?" came out one year later. It had politicized content and the band started to get more fans. In early 1987, Megadeath supported Alice Cooper and then they followed their own tour in the UK and USA. Before the tour finishes, Samuelson who couldn't control his drug addiction, along with Poland were fired later that year. Chuck Behler replaced Samuelson and Jeff Young became the new guitarist.
The next album was " So Far, So Good... So What!", which came out in early 1988. They toured with Dio and Iron Maiden and they performed to "Monsters of Rock" fest. Then, Mustaine dismissed Young and Behler and the later was replaced by Nick Menza. When the band was looking for a new guitarist, the police caught Mustaine with drugs and he was forced by the law to follow a drug treatment program. Marty Friedman was the new drummer and their next album "Rust in Peace", came out in 1990. The album continued their successes, including the hits " Holy Wars... The Punishment Due" and "Hangar 18". It was nominated for "Best Metal Performance" in the Grammys ceremony of 1991, while Megadeath had followed "Clash of the Titans" tour, along with Slayer, Anthrax and other.
Megadeath's most successful album is "Countdown to Extinction" that came out in the summer of 1992, reaching the second place on the US album chart. It was nominated for the "Best Metal Performance" Grammy Award, while among its hits are " Symphony of Destruction" and " Sweating Bullets". The next two successful albums were 1994's "Youthanasia" and 1997's "Cryptic Writings". The second contains the hit "Trust", which won another Grammy nomination. During the "Ozzfest" tour in 1998, Menza had to do surgery. Jimmy DeGrasso took his place but later Menza was sucked by Mustain. Their next album, "Risk"(1999) wasn't very successful, although it included the hit "Crush 'Em". Al Pitrelli replaced Friedman in 2000 and after the tours that followed the album "The World Needs a Hero", Mustaine dissolved the band in 2002, due to his kidney stone disease. He returned in 2004 with session members.
In the following years Megadeath released another seven studio albums along with five live and six collaboration albums. Their current line-up apart from Mustaine and Ellefson includes Kiko Loureiro (guitar) and Dirk Verbeuren (drums). They belong to the concept "Big Four" which includes Metallica, Slayer and Anthrax, as the most popular American thrash metal bands.