From 1991 to 2002, we managed 72 patients with mucopolysaccharidoses. We retrospectively reviewed the records of 37 for whom detailed physical findings and cardiovascular evaluation were available. Twenty patients had serial electrocardiographic (ECG) examinations, and none had arrhythmias. All 20 patients had low R wave voltage in V6. One type VI patient had ischaemic changes secondary to severe cardiomyopathy at the terminal stage of her disease. Among the 37 patients in whom echocardiography was performed, cardiovascular abnormalities progressed with age, although most had mild clinical signs and symptoms. The most common changes were abnormalities of the mitral and aortic valves hypertrophy of the interventricular septum, especially in types I, II, and VI. During the follow-up period of up to 5 years, 3 type II patients and I type VI patient expired. In at least 3 of these patients, death was related to cardiopulmonary failure. As MPS patients are surviving longer, complete cardiac evaluation at regular intervals is mandatory and should be part of their routine assessment.