In this study, we present a case of late-puerperal onset of thrombohemorrhagic complications in a 33-yr-old woman with known antiphospholipid syndrome (APS) and heterozygosity for factor V Leiden gene mutation. Antithrombotic prophylaxis with low-molecular-weight (LMW) heparin was given since the 12th gestational week. Pregnancy and cesarean delivery were uncomplicated. Five weeks postpartum, the patient developed a severe hemorrhagic diathesis with marked thrombocytopenia accompanied by vaginal, nasal and cutaneous bleeding. A variety of autoimmune phenomena were also detected, partly at clinical presentation and partly later on, despite ongoing steroid treatment. Platelet counts recovered to normal values within a few weeks secondary to high-dose steroids and intravenous immunoglobulin administration. An ultrasound of both legs, performed because of persistent complaint of moderate calf pain, revealed bilateral deep venous thromboses (DVT). The clinical and biochemical findings were not consistent with thrombotic thrombocytopenic purpura (TTP), heparin-induced thrombocytopenia (HIT) or the 'hemolysis, elevated liver enzymes and low platelet syndrome' (HELLP). The diagnostic criteria for systemic lupus erythematosus (SLE) were not fulfilled either. The complex of thrombohemorrhagic complications and autoimmune phenomena seen in this case is unusual and not previously described in the late puerperal stage of APS-related pregnancies.