OBJECTIVE: The primary purpose of this research was to assess the rates of axis I and axis II psychiatric disorders, as defined in DSM-IV, in a group of pedophilic sex offenders. METHOD: Forty-five male subjects with pedophilia who were participating in residential or outpatient sex offender treatment programs were recruited to participate. Subjects were interviewed by using the Structured Clinical Interview for DSM-IV. RESULTS: Ninety-three percent of the subjects (N=42) met the criteria for an axis I disorder other than pedophilia. The lifetime prevalence of mood disorder in this group was 67%. Sixty-four percent of the subjects met the criteria for an anxiety disorder, 60% for psychoactive substance use disorder, 53% for another paraphilia diagnosis, and 24% for a sexual dysfunction diagnosis. CONCLUSIONS: Axis I and II comorbidity rates are high in this population. Untreated comorbid psychiatric disorders may play a role in treatment failure and recidivism.