This study reports on a population of early adolescent male sexual offenders 9 to 14 years of age compared with a clinic control group matched for age, sex, ethnic status, and the presence of a DSM-III-R conduct disorder. The sex offenders were found to exhibit a significant history of nonsexual antisocial behavior, physical and sexual abuse, and psychiatric comorbidity. The two groups did not differ in number and category of comorbid psychiatric diagnoses, the number of nonsexual aggressive and nonaggressive symptoms of conduct disorder, symptoms of major depressive disorder or dysthymia, and symptoms of anxiety disorders. The EGTC group demonstrated significantly lower mathematic achievement. There is evidence that sexual offending behavior in this population is one aspect of a pattern of antisocial behavior. Sixty-five percent of the index group had a history of early sexual victimization.