Research on psychiatric morbidity in sexual offenders (SOs) has mostly been based on small, selected samples. We studied psychiatric disorders and their relationship with criminal recidivism in a nationwide, representative cohort of SOs. Data on ICD-9 and -10 psychiatric and neurologic morbidity diagnosed during hospital admissions 1987-1997, but prior to sexual offending, were retrieved for all adult male SOs released from Swedish prisons 1993-1997 (N = 1215). Preoffending disorder prevalence and associations between morbidity and criminal reconvictions during a 5-year postdetainment follow-up were explored. Alcohol use disorder was the most frequent diagnosis, followed by drug use disorder, personality disorder, and psychosis. Morbidity requiring admission to hospital was more common in rapists as compared to child molesters. Alcohol use disorder, drug use disorder, personality disorder, and psychosis all increased the risk for sexual recidivism whereas alcohol use disorder and personality disorder predicted violent nonsexual recidivism. Controlling for sociodemographic confounds changed the risk estimates only marginally. Because disorders were identified among only those who had been admitted to psychiatric hospitals as inpatients, underestimation of true prevalence rates was inevitable. However, our findings support psychiatric consultation for improved assessment and management of mental health needs and recidivism risk in SOs.