Unlike the Libman-Sacks vegetations of acute systemic lupus erythematosus (SLE), which are usually asymptomatic, valve involvement in chronic SLE and primary antiphospholipid antibody syndrome (APLAS) is similar to that of chronic rheumatic disease. Typical findings include valve thickening and nodularity, poor coaptation, and regurgitation. Elevated levels of antiphospholipid antibodies have been associated with the development of these valvular abnormalities in some but not all reported cases, and there are undoubtedly other etiologic cofactors. When cardiac valvular replacement is required, special attention must be given to preoperative reduction of elevated antibody levels, prevention of intraoperative thromboembolism, and prompt and aggressive postoperative anticoagulation.