A 52-year-old woman with traumatic rupture of the thoracic descending aorta had a history of previous blood transfusion 23 years ago. This time, she received 4,600 ml of blood transfusion during the replacement procedure of thoracic aorta. On the 12th postoperative day, she had acutely progressive severe jaundice, anemia and hepatosplenomegaly. All transfused blood was compatible by bromelin method before operation. Serological studies revealed a secondary response of hemolytic transfusion reaction due to anti E and anti c antibodies. She fell into severe bilirubinemia (66 mg/dl) and anuria, and died on 19th day after operation. A positive Coombs test in a patient who has been transfused recently must be interpreted with great caution. The "coated" cells may be incompatible donor cells in a patient who has antibodies from a prior transfusion. The incompatibility occasionally leads to delayed transfusion reaction that may stimulate "autoimmune" hemolytic anemia.