Anomalous origin of the left coronary artery from the pulmonary artery (the Bland-White-Garland syndrome) is a rare congenital cardiac defect which may present for the first time in adulthood. The recognition of this disorder, which produces widespread left ventricular ischaemia and the risk of sudden death, myocardial infarction and congestive heart failure, is important as the prognosis can be improved by surgical intervention. Thallium-201 scintigraphy has a useful role in demonstrating the widespread nature of the ischaemia of the left ventricle, whilst the diagnosis is confirmed at cardiac catheterisation.