Thrombotic thrombocytopenic purpura (TTP) is an unusual syndrome characterized by a clinical picture of micro-angiopathic hemolytic anemia, thrombocytopenic purpura, neurologic symptoms, renal disease and fever. Although widespread vascular thrombosis is common in TTP, the evidence of cardiac involvement is less clear. We report the first Korean case of a 22-year-old woman with TTP associated with acute myocardial infarction. With continued plasmapheresis, the clinical status of TTP improved markedly and was stabilized. Serial echocardiograms showed improvement of the cardiac wall motion.