Blood or marrow transplantation (BMT) has been utilized as a cancer therapy with varying levels of success. While it has been an important option for many hematological malignancies, it has met with less success in solid tumors. More recently, new combinations of therapies with BMT have been developed to enhance the efficacy of this therapy and to expand the number of target tumors. This review highlights current uses of BMT, rationales for experimental approaches using BMT alone or as a part of a combination therapy, and reviews some of the novel therapies that have been developed in tumor immunotherapy with BMT, in addition to the implications for translation.