We report a 32-year-old female patient with antiphospholipid syndrome including severe coronary artery disease and multiple arterial and venous thrombosis. The patient had occlusion of the right internal thoracic artery, diffuse stenosis of the left internal thoracic artery, and occlusion of the left saphenous vein. The patient underwent successful coronary artery bypass grafting using the right gastroepiploic artery and a segment of the right saphenous vein. Antiphospholipid syndrome should be considered in young patients with myocardial infarction.