Connective tissue diseases encompass a wide group of nosologic entities of unknown etiology, characterized by multisystemic organ involvement, sharing an immunologic pathogenetic mechanism, producing a variety of inflammatory manifestations, and whose primary lesion is always a diffuse vasculitis. Any part of the cardiovascular system may be involved, including the pericardium, the myocardium, the endocardium and valves, the coronary arteries, the aorta, the pulmonary vasculature, the peripheral arteries, veins, arterioles, venules, and the capillary beds of almost every organ subsystem. Pathologic studies disclose a high prevalence of heart involvement, but the presence and extent of pathologic findings correlate poorly with clinical manifestations. With the advent of echocardiography-Doppler, milder and earlier cases are now recognized. Although these patients continue under the care of rheumatologists and internists, when cardiac involvement arises, cardiologists must be aware of the characteristics, outcome and management of connective tissue diseases.