Killing Is My Business... and Business Is Good! is the debut studio album by American thrash metal band Megadeth. It was released on June 12, 1985, through Combat Records. At the beginning of 1985, the band was given $8,000 by Combat to record and produce their debut album. After spending half of the album's budget on drugs, alcohol and food, the band was forced to fire their original producer and produce the album themselves. Despite the resulting poor production, the album was a well-received effort that obtained strong reviews in various music publications. Killing Is My Business... and Business Is Good! played an essential role in establishing thrash metal as an authentic sub-genre of heavy metal music. It explores themes of death, violence and occultism.
The album features a controversial cover of "These Boots Are Made for Walkin'" and the track "Mechanix", a song Dave Mustaine originally wrote for Metallica. A deluxe edition, completely remixed and remastered with several bonus tracks, was released through Loud Records in 2002. It features vastly different artwork, with its cover based on the version originally designed by Mustaine in 1985. All songs from the album have been performed frequently during Megadeth's initial tour, but have been steadily dropped from the setlist afterwards.