In the following article three cases of supravalvular aortic stenosis are presented: the first two cases refer to two brothers. The older, a 22-year-old man presenting with palpitations, underwent echocardiography and Doppler that showed an hour-glass supravalvular aortic stenosis with a peak gradient of 115 mmHg, associated with dilation of the left main coronary artery and stenosis of the left carotid artery at its origin. The patient's family was evaluated by echocardiography, and an 18-year-old brother was similarly found to have an hour-glass supravalvular aortic stenosis, graded mild to moderate (peak gradient 40 mmHg). Both cases are probably familiar forms of supravalvular aortic stenosis with normal facies and intelligence (autosomal dominant transmission). The elder brother, with severe stenosis, underwent surgical replacement of the ascending aorta. The third patient was a 23-year-old woman with a previous diagnosis of congenital aortic stenosis. Her characteristic elfic facies induced us to suspect the syndrome of Williams-Beuren; transthoracic and transesophageal echocardiographic examination showed an hour-glass supravalvular aortic stenosis with a peak gradient of 60 mmHg. Magnetic resonance imaging showed hypoplasia of the descending aorta and the iliac arteries. Since she was asymptomatic and presented only with a moderate gradient, the patient was not referred to surgical therapy. In this manuscript we present the three cases and review the histopathological, clinical, genetic, diagnostic and therapeutic aspects of this disease and its natural history.