Prior research has documented high rates of anogenital and physical injuries among adolescent sexual assault patients. Although a number of factors related to rates of injury detection in adolescents have been identified, there may be additional features of the assault that are disclosed in the patient history that could be important indicators of injury risk. The purpose of the current study was to expand this literature by examining whether factors that are salient in sexual assaults committed against adolescents—victim–offender relationship, substance use, and memory impairment—are associated with documented anogenital and physical injury rates. Results indicated that victim–offender relationship, substance use, and assault memory are significantly related to the number of anogenital injuries and, particularly, the number of physical injuries detected in adolescent sexual assault patients. These results highlight the importance of a comprehensive patient history, including assessment of alcohol and drug use and memory impairment, to guide the medical forensic examination.