• Schizophrenic patients referred for day treatment at the time of discharge from ten hospitals were randomly assigned to receive day treatment plus drugs or to receive drugs alone. They were tested before assignment and at 6, 12, 18, and 24 months on social functioning, symptoms, and attitudes. Community tenure and costs were also measured. The ten day centers were described on process variables every six months for the four years of the study. Some centers were found to be effective in treating chronic schizophrenic patients and others were not. All centers improved the patients' social functioning. Six of the centers were found to significantly delay relapse, reduce symptoms, and change some attitudes. Costs for patients in these centers were not significantly different from the group receiving only drugs. More professional staff hours, group therapy, and a high patient turnover treatment philosophy were associated with poor-result centers. More occupational therapy and a sustained nonthreatening environment were more characteristic of successful outcome centers.