Between August 2008 and August 2011, nine patients (3 girls, 6 boys; mean age 19 +/- 29 months) were admitted to our clinic with Williams syndrome. The mean body weight of the patients was 9454 +/- 5880 g. Two patients had supravalvular aortic stenosis (sAS), one had periferal pulmonary stenosis (PPS), one had supravalvular PS (sPS), two had sAS and sPS, and three had sAS and bilateral PPS. Two patients were not operated. Four patients were operated for sAS and PPS, one patient for sAS, valvular and sPS, one patient for PPS and sPS, and one patient for sAS operation. The gradients were decreased and remained unchanged during follow-up.