Antiphospholipid antibody syndrome is characterized by arterial or venous thrombosis associated to the presence of antiphospholipid antibodies. We report a 32 atrial thrombus. Four months later, being with anticoagulant treatment, he had a deep venous thrombosis. A new echocardiogram did not show the atrial thrombus. The laboratory work-up confirmed an antiphospholipid syndrome. Five months later the patient has not presented new thrombotic episodes and is receiving oral anticoagulants and antiplatelet therapy.