We investigated the prevalence of obsessive-compulsive disorder (OCD) among patients who were primarily diagnosed with schizophrenia. We investigated the differences in the neuropsychiatric features and motor symptoms between patients with schizophrenia who did or did not have OCD. Seventy-one subjects with the DSM-IV diagnosis of schizophrenia were evaluated by the Structured Clinical Interview for DSM-IV Axis I Disorders, the Yale-Brown Obsessive-compulsive Scale and the Positive and Negative Syndrome Scale. To assess their motor symptoms, the Abnormal Involuntary Movements Scale, the Barnes rating scale for drug-induced akathisia and the Simpson and Angus extrapyramidal symptoms (EPS) rating scale were used. The 13 subjects with OCD (18.3%) had significantly more severe motor symptoms than the non-OCD subjects. Patients with schizophrenia who exhibit moderate to severe motor symptoms as side-effects of neuroleptics, should be examined for OCD comorbidity. Patients who are found to have OCD comorbidity must be treated with carefully chosen medications, including serotonin re-uptake inhibitors.