Review of autopsy data for 218 white men between 20 and 39 years of age who died of injuries or suddenly and unexpectedly indicated a mean heart weight of 371 g. The mean for those dying of external causes was 364 g whereas the mean for those dying of natural causes was 446 g. A coefficient for heart weight expressed as a percentage of body weight was lower in heavy individuals than lightweight individuals; it ranged between 0.38% and 0.55%, with a mean of 0.48%. Heart weight, including epicardial fat, increased with age and body weight. These data may be useful to those who are called upon to investigate sudden and unexpected deaths.