A trial of brief group therapy as part of a rehabilitation program for postmyocardial infarction (MI) patients was carried out. Forty-four patients surviving their first MI were randomly allocated to either group therapy or control group status and were followed over 4 years. An additional group of 17 patients were referred for post-MI group therapy sessions after the termination of the controlled experiment and were followed for 3 years. Patients who received group therapy had significantly less follow-up coronary morbidity and mortality, and returned to work at significant higher percentages than control patients. Although neither group therapy nor control group patients meaningfully altered conventional coronary risk factors, group therapy patients (in the controlled trial) successfully altered selected coronary-prone behaviors. Educational information regarding the physiological and psychological aspects of coronary heart disease, presented in the group therapy sessions, was forgotten over follow-up. It is concluded that the supportive aspects of the group therapy experience played the most important role in determining the rehabilitation advantages seen for treatment patients.