An infant presented with features suggestive of an anomalous left coronary artery was found to have normal origins of both coronary arteries. Echocardiography during episodes of ischaemia showed marked aortic regurgitation with retrograde coronary flow. The left coronary leaflet was mildly hypoplastic. Surgical re-suspension of this leaflet prevented aortic regurgitation and the patient had no further symptoms and recovered cardiac function.