Dave Mustaine was born in La Mesa, California in 1961, in what can be described as a broken home. His parents divorced when he was 7 and he spent most of his childhood bouncing around various homes, sometimes living with his sisters and brothers-in-law. In 1981, Mustaine helped create Metallica with Lars Ulrich and James Hetfield. Mustaine played lead guitar for two years, and stayed with the band during the formative years, laying the groundwork that led to Metallica's eventual success. But personal conflicts arose between the members, resulting in Mustaine's departure.

Mustaine immediately partnered up with bassist Dave Ellefson and formed Megadeth, while drummer Lee Rash and guitarist Kerry King soon joined. Mustaine became the songwriter, singer and guitarist for the band, and has remained in that position for more than 20 years now. In the first two years of inception, the band toured, developed a fan base, and eventually signed with an independent label. The success of their first album, Killing Is My Business... And Business Is Good!, led to the band signing with Capitol Records. Their major label debut, 1986's Peace Sells... But Who's Buying?, created the kind of buzz that catapulted them to platinum sales and "heavy metal gods" status. Since then, Megadeth has released numerous hits, developing a loyal following in the process.

In April of 2002, Mustaine suffered a serious injury, leaving him without the use of his left hand. He has since recovered and is now stronger than ever. Over the course of the band's lifetime, the lineup has changed many times, however, Mustaine is the last original member standing.