All aspects of blood transfusion are dealt with comprehensively, making it a ready reckoner in case a surgeon has to refer to a book suddenly in the event of facing a transfusion reaction. Real life incidences are quoted to start the chapter, going on to haemolytic reaction, which is dealt with in detail, describing its subtypes. Febrile nonhaemolytic reactions are then described. Allergic Transfusion Reactions and their grading and Transfusion related acute lung injury (TRALI) are described in detail. Circulatory overload, bacterial contamination and tricky situations necessitating massive transfusions leading to hypothermia, and citrate toxicity are described. Delayed transfusion reactions like haemolysis, infection, and thrombocytopenia are also described.