The efficacy and safety of adding fluvoxamine to antipsychotic treatment in schizophrenic patients with mixed positive and negative symptoms was examined. Fifty-three patients selected for persistent negative and positive symptoms who were receiving antipsychotic treatment were randomly allocated to additional fluvoxamine (50-100 mg / day) or placebo in a double-blind manner. Fluvoxamine was associated with significant improvement in negative symptoms (Scale for the Assessment of Negative Symptoms) compared to placebo. The combination was well tolerated. Fluvoxamine augmentation of antipsychotics is safe in chronic schizophrenic patients with mixed positive and negative symptoms and may ameliorate negative symptoms in such patients.