Killing Is My Business... and Business Is Good! is the debut studio album by American thrash metal band Megadeth, released on June 12, 1985, by Combat Records. At the beginning of 1985, the band was given $8,000 by Combat to record and produce its debut album. The band was forced to fire their original producer and produce the album by themselves, after spending half of the album's budget on drugs, alcohol, and food. Despite the 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 subgenre of heavy metal music. It explores themes of death, occultism, and violence.

Megadeth is an American thrash metal band formed in Los Angeles in 1983 by vocalist/guitarist Dave Mustaine. Known for their technically complex guitar work and musicianship, Megadeth is one of the "big four" of American thrash metal along with Metallica, Anthrax, and Slayer, responsible for the genre's development and popularization. Their music features complex arrangements and fast rhythm sections, dual lead guitars, and lyrical themes of war, politics, religion, death, and personal relationships.