Antiphospholipid syndrome (APS) is an acquired systemic autoimmune disorder characterized by a combination of clinical criteria, including vascular thrombosis or pregnancy morbidity and elevated antiphospholipid antibody titers. It is one of the causes of deep vein thrombosis and pulmonary embolism that can be critical due to the mortality risk. Overall recurrence of thromboembolism is very low with adequate anticoagulation prophylaxis. The most effective treatment to prevent recurrent thrombosis is long-term anticoagulation. We report on a 17-year-old male with APS, who manifested blue toe syndrome, deep vein thrombosis, pulmonary thromboembolism, and cerebral infarction despite adequate long-term anticoagulation therapy.