Antiphospholipid antibodies are associated with venous and arterial thromboembolism and with fetal loss. These associations are found either in autoimmune disease or without any other associated disease. In the first case one will speak of secondary antiphospholipid syndrome and in the second of primary antiphospholipid syndrome. The detection techniques of these antibodies have been improved these last years, although they remain difficult to standardize. The treatment of thromboembolism is based on the use of heparin and oral anticoagulants. Several therapeutic options exist to treat fetal losses, among which corticosteroids, subcutaneous heparin and aspirin are the most frequently used.