A 38 year-old man with a 12-year history of noninsulin-dependent diabetes mellitus with rapidly progressive diabetic complications presented with microangiopathic hemolytic anemia and thrombocytopenia. He had no disorders that could induce microangiopathic hemolytic anemia other than diabetic microangiopathy. In addition, there was a significant negative correlation between serum lactate dehydrogenase levels and peripheral platelet counts, which suggested that the hemolysis and thrombocytopenia occurred through the same mechanism. Activated partial thromboplastin time was slightly prolonged, and lupus anticoagulant and antiphospholipid immunoglobulin G antibodies were positive. Both the hemolysis and the thrombocytopenia spontaneously improved after the initiation of hemodialysis. This is a unique case of diabetic microangiopathic hemolytic anemia and thrombocytopenia in which antiphospholipid syndrome also may be involved.