We report a case of two consecutive episodes of acute hemolytic transfusion reactions (HTRs) due to multiple alloantibodies in a 34-yr-old man who suffered from avascular necrosis of left femoral head. He received five units of packed red blood cells (RBCs) during surgery. Then the transfusion of packed RBCs was required nine days after the surgery because of the unexplained drop in hemoglobin level. The transfusion of the first two units resulted in fever and brown-colored urine, but he received the transfusion of another packed RBCs the next day. He experienced even more severe symptoms during the transfusion of the first unit. We performed antibody screening test, and it showed positive results. Multiple alloantibodies including anti-E, anti-c and anti-Jk^b were detected by antibody identification study. Acute HTRs due to multiple alloantibodies were diagnosed, and the supportive cares were done for 6 days. We suggest the antibody screening test should be included in the panel of pretransfusion tests for safer transfusion, and it is particularly mandatory for the patients with multiple transfusions, pregnant women, and preoperative patients.