A 69-year-old woman with systemic sclerosis developed thrombosis of each superficial femoral artery requiring above-knee amputations. On pathologic examination of the involved vessels, atherosclerotic changes were minimal and thrombus formation was the primary abnormality. The presence of antiphospholipid antibody suggested an acquired predisposition to vascular thrombosis. Prior reports of large vessel thrombosis in systemic sclerosis are reviewed.