Some studies suggest that obsessive-compulsive symptoms may be common (7.8-46%) in schizophrenic patients and seem to be poorly responsive to drug therapy. Conventional neuroleptics are of limited value, but adjunctive anti-obsessive agents (clomipramine, fluvoxamine) may be an option. Although novel atypical antipsychotics (clozapine, risperidone) reportedly aggravate the obsessive-compulsive symptoms, a recent trial has shown that olanzapine did not induce new-onset obsessive-compulsive symptoms in schizophrenic patients. We report our experience with three schizophrenic patients with obsessive-compulsive symptoms who were unsuccessfully treated with various conventional neuroleptics in combination with anti-obsessive agents and subsequently showed resistance or intolerance to clozapine. All of them were switched to olanzapine (10-20 mg/ day). All patients demonstrated a significant improvement in both schizophrenic and obsessive-compulsive symptoms as measured by the Brief Psychiatric Rating Scale (BPRS) and the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Within 5-8 weeks of initiation of olanzapine, the BPRS scores of the three patient decreased by 53%, 51% and 48%, and the Y-BOCS scores by 68%, 73% and 85%. Olanzapine was well tolerated. These preliminary results suggest that olanzapine may be a therapeutic option in schizophrenic patients with obsessive-compulsive symptoms.