This report describes the cardiac involvement of patients with mucopolysaccharidoses Type II (Hunter disease). Mucopolysaccharidoses Type II are an uncommon group of about 50 rare inherited metabolic disorders, that result from defects in lysosomal dysfunction, usually as a consequence of deficiency of a single enzyme required for the metabolism of lipids, glycoproteins or so called mucoplysaccharides. Most of this diorders are autosomal recesively inherited such as Hunter syndrome Mucopolysacharidosis. Tuype II is a lisosomal storage disease caused by a deficiency of the lysosomal ensyme iduronate 2 sulfatase. its frequency is 1 to 100.000 to 150.000 male births; is farmore common in boys. Clinical, electrocardiographical and sonographical variables were determined. As a result 18 patients were evaluated; all the patients presented cardiac involvement. Color Doppler sonocardiogram was pathological in the 100% of the patients, and 4 of them, showed mitral/and or aortic, and 4 patients with miocardic hypoertrophy, and 1 patient, pulmonary hipertension. A clinical review is prsented, and a guide for management is detailed (AU)