There has been considerable debate as to the risk of suicide, accidents, and homicide in populations at high risk for HIV infection. The purpose of the present investigation was to determine the incidence of sudden and unexpected deaths in a well-defined cohort of homosexual and bisexual men prospectively studied since 1984. All subjects were enrolled in the Pitt Men's Study, the Pittsburgh, Pennsylvania, component of the Multicenter AIDS Cohort Study. Of this group, 861 were between the ages of 20 and 44, and 35% were seropositive for HIV. There were 70 deaths attributed to AIDS. Five additional deaths were classified as sudden and unexpected, an annual rate of 0.08% (80/100,000). Only one of these was classified by the coroner's office as a suicide; three were due to accidents, and one was a drug overdose of undetermined cause. Only two of the five unexpected deaths were HIV seropositive, and none had the diagnosis of AIDS. The sudden and unexpected death rate in this cohort did not significantly differ from the 0.07% (70/100,000) yearly incidence in the age- and race-matched male population. Thus, in this well-defined male gay cohort, there does not appear to be an increased risk of violent and drug-related deaths in persons at risk for, or with a diagnosis of, AIDS.