Organomegaly can be a sign of disease and pathologic abnormality, although standard tables defining organomegaly have yet to be established and universally accepted. This study was designed to address the issue and to determine a normal weight for the major organs in adult human males. A prospective study of healthy men aged 18 to 35 years who died of sudden, traumatic deaths was undertaken. Cases were excluded if there was a history of medical illness including illicit drug use, if prolonged medical treatment was performed, if there was a prolonged period between the time of injury and death, if body length and weight could not be accurately assessed, or if any illness or intoxication was identified after gross and microscopic analysis including evidence of systemic disease. Individual organs were excluded if there was significant injury to the organ, which could have affected the weight. A total of 232 cases met criteria for inclusion in the study during the approximately 6-year period of data collection from 2005 to 2011. The decedents had a mean age of 23.9 years and ranged in length from 146 to 193 cm, with a mean length of 173 cm. The weight ranged from 48.5 to 153 kg, with a mean weight of 76.4 kg. Most decedents (87%) died of either ballistic or blunt force (including craniocerebral) injuries. The mean weight of the brain was 1407 g (range, 1070-1767 g), that of the liver was 1561 g (range, 838-2584 g), that of the spleen was 139 g (range, 43-344 g), that of the right lung was 445 g (range, 185-967 g), that of the left lung was 395 g (range, 186-885 g), that of the right kidney was 129 g (range, 79-223 g), and that of the left kidney was 137 g (range, 74-235 g). Regression analysis was performed and showed that there were insufficient associations between organ weight and body length, body weight, and body mass index to allow for predictability. The authors, therefore, propose establishing a reference range for organ weights in men, much like those in use for other laboratory tests including hemoglobin, hematocrit, or glucose. The following reference ranges (95% inclusion) are proposed: brain, 1179-1621 g; liver, 968-1860 g; spleen, 28-226 g; right lung, 155-720 g; left lung, 112-675 g; right kidney, 81-160 g; and left kidney, 83-176 g.