This paper shows 21 patients with antiphospholipid syndrome, that were diagnosed after thrombosis, recurrent fetal loss or thrombocytopenia. Lupus anticoagulant was detected in 18, anticardiolipin antibodies in 15 and VDRL test was positive in 6 patients. Nine patients had recurrent venous thrombosis, 6 pulmonary embolus, 9 recurrent fetal loss and 15 were with low platelet count. Secondary prevention with oral anticoagulants was applied according to the level of INR 2.5-3.5. Only one patient relapsed due to deficient anticoagulation. Three pregnant patients were treated with aspirin, and low molecular weight heparin, alone or in combination with prednisone. All of them had recurrent spontaneous abortions between 20 and 28 weeks of gestation. In conclusion, early diagnosis of antiphospholipid syndrome is very important. Secondary prevention of thromboembolic complications is recommended according to the level of INR > or = 3. For the prevention of fetal loss we have not agreed upon treatment of all patients. Further studies are needed to define more precisely the optimal type, intensity, and the duration of therapy.