Major depression is found in one fifth of heart failure patients, and clinically significant depressive symptoms in almost half. The association of depression and heart failure appears to be related both to the psychological aspects of severe heart disease, and to pathophysiological and psychosocial mechanisms. The presence of depression is associated with a worsening of the prognosis, and increased risk of death, rehospitalization, and functional decline. Detection and treatment of depression should be part of a comprehensive approach to heart failure patients by cardiologists and family doctors. Good quality cardiac care should include psychosocial assessment, strengthening of the doctor-patient relationship and of family and social bonds, and, when appropriate, antidepressants and psychotherapy. Selective serotonin reuptake inhibitors are effective and safe antidepressants in cardiac patients. They should be prescribed in therapeutic doses until sustained remission is obtained. Collaboration between psychiatrists and other specialists at primary and secondary care levels is recommended and contributes to better quality care.