The leading causes of death (rate per 100,000 prisoner-years) in Maryland state prisons for the period 1979-87 were circulatory system disease (59), suicide (40), and homicide and legal intervention (30). Acquired immunodeficiency syndrome (AIDS) became the leading cause of death in 1987. Homicides declined after 1980; drug overdose deaths peaked in 1981 and later disappeared. Male inmates have 39 percent lower all-cause death rates than the general population of Maryland after adjustment for age and race.