The aim of the catch-up follow-up study is to describe the long-term outcome of obsessive-compulsive disorder (OCD) with onset in childhood and adolescence. The psychiatric morbidity in adulthood including personality disorders was assessed and predictors in childhood for the course of obsessive-compulsive symptoms were examined. The total study group consisted of the entire patient population treated for OCD at our departments for child and adolescent psychiatry between 1980 and 1991. We reassessed 55 patients personally by way of structured interviews. The mean age of onset of OCD was 12.5 years and the mean follow-up time was 11.2 years. At the follow-up investigation 71% of the patients met the criteria for some form of psychiatric disorder, while 36% were still suffering from OCD. Of the patients with a present diagnosis of OCD 70% had at least one further clinical disorder (especially anxiety and affective disorders). The most frequent personality disorders diagnosed were obsessive-compulsive (25.5%), avoidant (21.8%), and paranoid (12.7%) personality disorders. In-patient treatment, terminating treatment against advice and tics in childhood or adolescence significantly correlated with more severe OC symptoms in adulthood.