Refusal of treatment with antipsychotic medication was studied prospectively in a sample of 1434 psychiatric patients admitted to four acute inpatient units in state-operated mental health facilities in Massachusetts during a 6-month period. Compared with a control group of patients who accepted prescribed antipsychotic treatment, the 103 patients who refused were older, of a higher social class, and less likely to have been prescribed antiparkinsonian medications. On admission, prior to refusal of medication, patients who refused were found to have significantly higher Brief Psychiatric Rating Scale scores than compliant patients and more negative attitudes regarding their hospitalization and past, present, and future treatment. Treatment refusal had negative effects on the hospital milieu and on the patient; refusers were more likely to require seclusion or restraint and had longer hospitalizations than treatment acceptors. Most refusal episodes ended with voluntary acceptance of treatment. In 23% of cases medications were discontinued. Only 18% of the sample reached formal, judicial review, and in every case that did, involuntary treatment was ordered. The policy implications of these findings are discussed.