Immunotherapy is the most recent therapeutic strategy in the treatment of cancer. It has not yet achieved an elevated curative efficiency and a wide clinical application. Nevertheless the possibilities of improvement seem very promising. The knowledge of the immune response mechanisms and the first clinical trials have determined a more efficient immunotherapy. Here we will critically analyze current immunotherapeutic strategies by reviewing the latest and the most important experimental works. The latest protocols of immunotherapy have been aimed to be more integrated in the physiological immune response schemes. The orientation of the experimental works have been changed from non specific immunotherapy using lymphokines to immunotherapy with specific lymphocytes expanded in vitro and, finally, the active specific immunotherapy in vivo by modificated tumoral vaccines or by variously manipulated tumoral antigens.