Clinical verification is being obtained, with a variety of different therapeutic approaches, for the concept that anticancer treatments based on exploiting the host's own antitumor defense mechanism can be beneficial. Nevertheless, as was seen with both chemotherapeutic and radiation treatments, the benefit of single agent treatments is not great. It is anticipated that, in attempting to realize the maximal potential of anticancer treatments based on exploiting the host's own antitumor defense mechanism, it will be necessary to utilize combination therapies. For medical-ethical reasons, the ability to effectively combine such treatments with ones with proven clinical efficacy should increase the enthusiasm for the initiation of clinical trials. Chemotherapeutic agents may serve this purpose, since, contrary to the generally held tenet that anticancer chemotherapeutic agents are merely immunosuppressive, there is considerable literature describing their ability to augment antitumor host defenses. This review attempts to collate this information derived by numerous investigators employing diverse experimental approaches with a number of the most widely used anticancer chemotherapeutic agents.