The postmortem finding of anal dilation or an exposed pectinate line in children who have died under suspicious circumstances continues to raise the concern of possible sexual abuse. The following multicenter, collaborative study was designed to help address that question. Sixty-five subjects, ranging in age from birth to 17 years, were autopsied at three different sites. A standard protocol along with 35-mm cameras were used to record the results. Thirty-eight (58%) subjects were boys, and 27 (42%) were girls. Forty-two (65%) were white, 10 (15%) African-American, five (8%) Asian, three (5%) white Hispanic, and five (8%) other. Fifty-seven (88%) were in Tanner stage I of secondary sexual development. Thirty-four (52%) died of natural causes, 26 (40%) from accidental injuries, three (5%) from other causes, and four (6%) as a result of a homicide. Forty-eight subjects (74%) had some dilation of the anal sphincters. In 21 children (32%), the entire anal canal, including the rectal ampulla, could be visualized. In another 21 (32%) subjects, the pectinate line was exposed. Only the outer portion of the anal canal opened in six children (10%), whereas 17 (26%) had no dilatation of the anus. Anal laxity led to flattened skin folds in 50 (77%), a shallow anal canal in 40 (62%), the exposure of both the pectinate line in 38 (59%), and the anal mucosa in 24 (37%). Venous congestion was present in 14 (22%), venous pooling in three (5%), erythema in six (9%), and increased pigmentation in eight (12%). Funneling was found in two (3%). Blood was present in three (5%), and an abrasion was discovered in one (2%). No fissures, lacerations, hemorrhoids, or scars were found in any of the children. Anal orifice size varied with the age of the child, the amount of traction applied to the buttocks, and a history of a CNS injury at the time of death. It is suggested, finally, that anal dilatation alone cannot be used as a marker for prior sexual abuse and that exposure of the pectinate line should not be confused with tears or fissures of the anal verge. Further studies of children known to have been sodomized prior to death are required.