The concept of targeted therapy was conceived through increased understanding of the biological pathways involved in the pathogenesis of cancer and subsequently identification of the most appropriate antigens to target. Monoclonal antibody therapy harnesses host defense mechanisms through activation of the antibody dependent cytotoxic pathway and complement mediated cytotoxicity. However, these two processes alone do not explain the therapeutic efficacy of antibody therapy; they also act by apoptotic signaling and growth inhibitory pathways. Conjugation of monoclonal antibody therapy, with radionuclides or toxins, offers more therapeutic approaches. Initial data demonstrates efficacy of single agent use, although combination therapy appears potentially more beneficial. Monoclonal antibody therapy is having a significant impact on many disease processes, particularly malignancies of solid and hematological origin. In this article, we shall review and discuss the monoclonal antibodies approved by the US Food and Drug Administration (FDA). in the management of cancer.