Clinically, the prognosis of nasopharyngeal carcinoma is very poor. It is considered that this depends on three factors. The first is the difficulty of early detection of this disease, because the symptoms of this cancer are latent. The second factor is the specificity of the histological character. The third is most important. This cancer cases fall into the extreme failure category of the immuno-surveillance mechanism. Immuno-responsiveness is extremely depressed. Immunological status has been examined and the clinical evaluation of immunotherapy with OK-432 (streptococcal preparation) and lymphocyte transfer has been made. Results are as follows: 1) Deficiencies of cellular immunity could be recognized through the various immunological parameters, such as subsets of peripheral blood lymphocytes. 2) Immunotherapy is indispensable in this cancer, for the above-mentioned reasons. Better results could be obtained with nonspecific immunotherapy, using OK-432. On the other hand, new immunotherapy, using immunologically enforced lymphocytes with Interleukin-2 prevented micrometastasis, one of the worst characteristics of this cancer. Nasopharyngeal carcinoma is a systemic disease. Therefore immunotherapy is indispensable for the treatment of this cancer.