Coronary arterio-systemic fistula is a rare condition, especially when multiple fistulae communicate with the left ventricule. The association of multiple congenital coronary artery-left ventricular fistulae and apical hypertrophy has not been previously reported. The authors report three cases, all in women, with multiple coronary artery-left ventricular fistulae and apical hypertrophy diagnosed by angiography. The association may not be coincidental as multiple microfistulae could cause abnormalities of the microcirculation and result in reactional myocardial hypertrophy.