Williams‐Beuren syndrome (WBS) is a multisystem congenital disorder, whose cardiovascular defects are the leading cause of death. We present the case of a 38‐year‐old man with features of heart failure. The imaging studies showed a typical supravalvular aortic stenosis and a hammock mitral valve, this last, being a rare congenital disease. This is the first case reported of a hammock mitral valve in a patient with this chromosomopathy.