Cancer immunotherapy (IT) started approximately 100 years ago with attempts to use a prepared immune serum against osteosarcoma. Since then, IT was attempted by use of various immunopotentiating agents like whole bacterial cells, bacterial cell fractions, cytokines and thymic humoral factors. The therapeutic efficiency of IT alone was limited and erratic. Accordingly, combined IT with other procedures were used. This included use of "immunomodulating" anticancer drugs as cyclophosphamide (CY) and melphalan (L-PAM) and use of IT in combination with tumor-reducing procedures like surgery, radiation and chemotherapy. The use of immunomodulating drugs was based on findings showing that CY and L-PAM enhance the ability of the immune system to react against tumor cells, in addition to their antitumor activity. Combined treatments were employed with the aim to reduce tumor-burden and as such, render IT more effective. Other therapeutic procedures consisted on use of specific antitumor antibodies as a vehicle for carrying radioactive lethal amounts to tumor cells, use of macrophages activated against tumor cells, use of prostaglandin antagonists and use of specific antitumor vaccines. The general conclusion is that while IT might have some beneficial therapeutic effect especially in conjunction with other procedures, it might be not sufficient to insure cure but it might increase the survival time and improve the quality of life of cancer patients.