Bland-White-Garland syndrome refers to the rare congenital cardiac abnormality whereby the left coronary artery arises from the pulmonary artery. The natural history of this condition is highly variable, ranging from death in early infancy to asymptomatic adult survival. It is sometimes diagnosed in adults with mitral regurgitation thought to be of ischaemic origin. We report a case of a 29-year-old man with Bland-White-Garland syndrome and concomitant mitral valve prolapse, and review the literature on the appropriate investigations and management of this abnormality. Recognition and diagnosis of this condition is important because of the potentially life-threatening complications, which may be prevented by surgical intervention.