Coronary artery-left ventricular fistulae are exceedingly rare and to date only 19 cases have been reported in the literature. We describe another four cases which we encountered recently. The first patient was a 10-year-old asymptomatic Indian male who was referred because of a to-and-fro murmur. Haemodynamic and angiographic studies revealed an aneurysmally enlarged right coronary draining into the left ventricle. The fistula was ligated and the patient has remained well over a 21/2-year follow-up period. The second patient was a 13-year-old asymptomatic Chinese female referred also because of a to-and-fro murmur. Haemodynamic and angiographic studies showed a grossly enlarged right coronary artery draining into the left ventricle. This patient refused operation and has remained well over a 2-year follow-up period. The third patient was a 43-year-old Chinese male who presented with a 3-year history of angina pectoris and was admitted to hospital because of crescendo angina. The resting electrocardiogram showed marked ischaemic changes and the treadmill exercise stress test was also positive. Selective coronary angiography showed markedly dilated right and left coronary arteries. Multiple fistulae from the three major coronary arteries were seen to communicate with the left ventricle. It was elected to treat this patient medically with propranolol. He has remained well over a 6-month follow-up period. The fourth patient was a 5-year-old asymptomatic Chinese girl. Cardiac catheterization and selective coronary angiography revealed marked dilatation of the branches of the left coronary artery which communicated via a maize of fine vessels into the left ventricle. This patient has remained well over a 5-year follow-up period. The clinical presentation, investigations and treatment of coronary artery-left ventricular fistula are discussed and the literature regarding this subject is reviewed.