Autoimmune diseases are occasionally associated with other autoimmune diseases in the same patients. Autoimmune Graves' disease has been associated with systemic rheumatic diseases including systemic lupus erythematosus(SLE). And Graves' disease associated with idiopathic thrornbocytopenic purpura(ITP) has been reported many times in Korea. There is a special relationship between SLE and ITP, both of which are autoimmune diseases. Some patients with thrombocytopenic purpura, labeled as idiopathic at the onset, later develop a classical course of SLE, suggesting that ITP may be an early manifestation of SLE. The relationships among these three conditions and their pathogenesis are poorly undemtood, and the coexistence of these diseases at the same time has been reported very rarely, but it may be very probable that there are some relationships among them. We report a case of SLE associated with Graves' disease and ITP treated well by imunosup- pressive agent who had been suffering from recurrence by conventional treatments(antithyroid medication, corticosteroid, subtotal thyroidectomy and splenectomy). (J Korean Soc Endocrinol 12:677-683, 1997)