The Years of Decay is the fourth studio album by thrash metal band Overkill, released on October 13, 1989, through Atlantic and Megaforce Records. It is the last Overkill album to feature guitarist Bobby Gustafson, who either left or was fired by the band amid a feud between himself and its founding members Bobby "Blitz" Ellsworth (vocalist) and D. D. Verni (bassist). The Years of Decay was also the first of two Overkill albums produced by Terry Date, who took on the same role for their follow-up album Horrorscope (1991).