The series of Veterans Administration Cooperative Studies in Psychiatry has provided continuing support for investigations of the role of the phenothiazines in the treatment of schizophrenic patients. This report is the result of the first cooperative project in geriatric psychiatry. I n the previous studies an upper age limit of 56 years was used; in the present investigation the patients were aged 54 to 74 years.The usefulness of phenothiazine therapy in younger, newly-admitted schizophrenic patients already has been demonstrated in several studies (1-3). Our one major investigation of depressed patients showed that imipramine was the most effective agent tested (4). The situation was less clear regarding the effect of combined drug therapy in patients with chronic schizophrenia ( 5 ) . For this group, the addition of dextro-amphetamine, imipramine or trifluoperazine to maintenance doses of chlorpromazine did not produce a therapeutic gain. Further study (6) revealed that discontinuation of phenothiazine medication in these patients resulted in a 45 per cent relapse rate over a period of sixteen weeks. Thus it may be concluded with confidence that treatment with the major phenothiazines is generally beneficial in schizophrenic patients under 56 years * Portions of this material were presented at the Ninth Annual Conference, VA Cooperative Studies in Psychiatry, by Marcus P. Rosenblum, MD., under the title, "Treatment of the Elderly Psychiatric Patient." The success of the VA program of Cooperative Studies in Psychiatry has depended upon the continued support of field-station personnel, whose tremendous effort is impossible to acknowledge in a footnote. The following list of VA hospitala and Principal Investigators who collaborated in this study must serve as the medium for expressing the gratitude of the authors to the hundreds of VA employees who contributed to this research.