Idiopathic dilated cardiomyopathy is a primary myocardial disease which is characterised by left ventricular, or biventricular, dilatation and impaired contractility. The precise aetiology is unknown and the relative contribution of genetic and environmental factors is debated. We report two identical male twins of Caucasian origin with idiopathic dilated cardiomyopathy who presented within a few months of each other.