A 28 year old woman with the Prader-Willi syndrome developed chest pain and loss of anterior R wave amplitude on the electrocardiogram. Cardiac catheterization demonstrated a severe proximal stenosis of the left anterior descending artery with delayed antegrade flow together with antero-apical akinesia consistent with myocardial infarction. Physicians involved in the management of patients with the Prader-Willi syndrome should be aware of this association with premature coronary artery disease.