Blood components are indicated in a wide variety of disease states. Although most transfusion therapies are administered uneventfully, there are a number of potential adverse transfusion reactions, some of which can assume serious dimensions. These reactions could occur during or even days after a transfusion. A brief description of the adverse effects of transfusion therapy has been outlined in this review. The etiopathogenesis, recognition and treatment of the adverse transfusion reactions have been highlighted. It is imperative that each transfusion of blood components has components be monitored carefully. Prompt recognition of an adverse event and early institution of remedial measures would help in decreasing transfusion related morbidity and mortality.