The antiphospholipid syndrome is a multiple-system disorder characterized by persistently elevated antiphospholipid antibodies and/or arterial or venous thrombosis, thrombocytopenia, or recurrent spontaneous abortion. Various cutaneous manifestations have been associated with this disease and may be the first sign of the underlying problem. We report a case of antiphospholipid syndrome with cutaneous ulcer on the left calf of a 21-year-old woman, who has been treated with deep vein thrombosis. (Korean J Dermatol 2000;38(10)：1358~1361)