Mortality data are presented from a 16- to 45-year follow-up study of 71 men with antisocial personality disorder. Death ascertainment was made through both a personal follow-up and use of the National Death Index. Comparisons were made with the mortality experience of the general population of the state of Iowa by using gender and age standardized mortality ratios. Seventeen men died (24%) died during the follow-up. Antisocial men younger than 40 years were at excessive risk for premature death (standardized mortality ratio [SMR] = 33, P < 0.25): men between ages 40 and 60 years also appeared to be at risk for premature death, although the excess was not statistically significant. Three subjects (18% of all deaths) died of complications from diabetes mellitus (SMR = 14, P < 0.05). Deaths were spread out among the four decades of follow-up. The findings and their implications are discussed.