BACKGROUND No previous reports have been published on the rate, frequency and nature of long-term sexual recidivism for a large cohort of Danish sexual offenders who have been through a forensic psychiatric evaluation. METHODS A retrospective follow-up study of all male sexual offenders evaluated between 1st January 1978 and 31st December 1992 at the Department of Forensic Psychiatry, Aarhus University Hospital, or at the Clinic of Forensic Psychiatry, Ministry of Justice, Copenhagen (n = 441). RESULTS Of the followed cohort (n = 342) 30% were sentenced for a new sexual criminal offence (including severe sexual acts), 17% for severe sexual acts, 32% for nonsexual violence and 61% for general crime during follow-up (average 16.5 years). There was a low rate of repeated sexual recidivism (12%) and severe sexual recidivism (6%). Extra-familial child molesters and exhibitionists had the highest risk of sexual recidivism and repeated sexual offences. Rapists had the highest risk of severe sexual recidivism and re-offended more rapidly than the other offender subgroups. Intra-familial child molesters had a low recidivism rate. Young offenders had a higher recidivism risk than older offenders. Severely mentally ill or retarded had a statistically lower rate of sexual recidivism than less disturbed offenders. CONCLUSIONS The sexual recidivism rate varies across sexual offender types. The management and prevention of sexual recidivism need to focus on treatment of sexual offenders with the highest risk of severe and repeated sexual offences.