Verapamil, a papaverine calcium channel blocker, has been used effectively and safely in the treatment of angina pectoris and auricular arrhythmias, and more recently in the treatment of mania. Many antipsychotic drugs show calcium channel blocking effects similar to verapamil's. A 41 year old male schizophrenic, only partially responsive to haloperidol decanoate and oral haloperidol, was given increasing doses of verapamil concomitantly, and monitored clinically and by the BPRS, electrocardiogramme, and other laboratory measures. The patient's total BPRS score dropped from 79 to 41 and remained stable, after initial worsening at lower doses, at verapamil 80 mg po qid. Mild fatigue was the only side effect. Further investigation of verapamil in the treatment of schizophrenia is warranted.