A 39-year-old parturient with idiopathic thrombocytopenic purpura (ITP) was scheduled for cesarean section at 37 weeks gestation. ITP, diagnosed during the first pregnancy, recurred during the second pregnancy, and she was treated with high dose gamma-globulin and platelets transfusion to increase her platelets count over 5.0 x 10(4) x microliter-1 before cesarean section. During the operation under general anesthesia with propofol and pentazocin, atonic hemorrhage occurred gradually with increasing blood loss after the parturition. Since administration of oxytocin, ergometrine maleate, and prostaglandin E1 could not improve the uterine contraction, the hysterectomy was performed to control massive bleeding (finally 8200 g). Packed red cells (22 units) and platelets (40 units) were transfused and fresh frozen plasma (28 units) was infused during anesthesia. Management of ITP during pregnancy is important to prevent hemorrhagic complications because of a narrow safety margin of parturient and fetus.