To review the contributions of clinical pharmacists to the care of psychiatric patients, we conducted a thorough MEDLINE review of the literature from January 1966 through January 1995. We recorded information regarding the number of patients, study designs, types of interventions, results, and cost savings. A substantial number of studies documented the positive effects of clinical pharmacists on patient outcomes, including improved care, improved level of functioning, and reduced medical and pharmaceutical care costs. Although more comprehensive studies have to be performed, a body of knowledge supports the pharmacist's role in the care of psychiatric patients.