Blood transfusion is an essential supportive treatment in modern medicine and is frequently used. Acute hemolytic transfusion reaction is prevented by conducting a cross-matching test; however, nonhemolytic transfusion reactions are difficult to predict. Furthermore, adverse transfusion reactions are not sufficiently recognized by healthcare workers because they rarely occur, except for urticaria and febrile reactions. Thus, further awareness of adverse reactions, particularly regarding transfusion-associated circulatory overload, is needed. Since the introduction of irradiated blood, no transfusion-associated graft-versus-host-disease (TA-GVHD) case has been reported for over 20 years. However, education on the risk of TA-GVHD is important in facilities where nonirradiated blood is supplied or in situations such as unavoidable in-house blood collection on remote islands. The incidence of transfusion-transmitted hepatitis was significantly decreased by the introduction of nucleic acid amplification tests. Recently, the Japanese Red Cross Society is focusing on the reduction of transfusion-associated bacterial infections, which are rare but serious complications. This review provides an updated overview of adverse transfusion reactions and their management measures. Understanding adverse transfusion reactions will enable healthcare workers to recognize symptoms and take prompt action.