Anomalous origin of the left main coronary from the pulmonary trunk in an elderly patient is extremely rare. We report a 73-year-old woman who presented with new onset of angina and atrial fibrillation. Evaluation revealed anomalous origin of the left main coronary artery from the main pulmonary artery and tight proximal left anterior descending coronary artery stenosis. The patient underwent primary closure of the anomalous left main coronary artery orifice within the pulmonary artery, aorta-to-left anterior descending coronary artery saphenous vein bypass grafting and Maze procedure. Six months postoperatively the patient was asymptomatic and a Thallium stress test was negative for ischemia.