Since emotional distress is linked to poor prognosis in coronary patients, there is urgent need for research into interventions that may enhance emotional well-being in these patients. Cardiac rehabilitation aims to return the individual to optimal emotional function, but the psychological effect of this therapy still needs to be demonstrated. Hence, we examined the role of cardiac rehabilitation in enhancing emotional health. We examined 170 male patients with coronary heart disease, of whom 85 had participated in the outpatient rehabilitation programme of the University Hospital of Antwerp and 85 had received standard medical care only in two other hospitals. Rehabilitation and control patients were matched by medical category and tendency to experience distress. The Global Mood Scale, the Health Complaints Scale, and the Heart Patients Psychological Questionnaire were used to assess changes in emotional well-being over a 3-month period. These changes were significantly different as a function of cardiac rehabilitation (P<0.0001). Rehabilitation patients, but not control patients, reported a significant improvement in negative affect, positive affect, well-being , health and disability (P<0.001). At follow-up, differences in depression, tranquillizer use (P<0.05), and activity profile (P<0.01) confirmed that rehabilitation patients displayed more healthy behaviour than control patients. Patients not only improved more, but also deteriorated less as a function of rehabilitation. This therapy also had a positive effect on patients suffering minimal distress, which is at variance with previous research. These findings suggest that comprehensive rehabilitation may be an effective therapy for enhancing emotional well-being in patients with coronary heart disease.