OBJECTIVE: The co-occurrence of obsessive-compulsive disorder (OCD) in adult patients with schizophrenia has been increasingly recognized. However, the rate of OCD comorbidity in adolescent schizophrenia patients has yet to be systematically evaluated. METHOD: The rate of DSM-IV OCD was evaluated in 50 adolescent inpatients with schizophrenia or schizoaffective disorder. The severity of schizophrenia and OCD symptoms was assessed with the Scale for the Assessment of Positive Symptoms, Scale for the Assessment of Negative Symptoms (SANS), and Yale-Brown Obsessive Compulsive Scale. RESULTS: Thirteen schizophrenia patients (26.0%) also met the DSM-IV criteria for OCD. This subgroup scored significantly higher on the SANS subscale for affective flattening or blunting. The total SANS score positively correlated with the total Yale-Brown Obsessive Compulsive Scale score. CONCLUSIONS: A substantial proportion of adolescent schizophrenia inpatients have concomitant OCD. A prospective study is needed to evaluate the clinical course, response to treatment, and prognosis for this complex disorder.