Accurate histologic determination of lymph node metastasis is most important in predicting prognosis in patients who undergo radical neck dissection. In this study of 340 determinate patients, the five year survival was 75 per cent when lymph nodes were histologically negative, 49 per cent when one lymph node was positive, 30 per cent when two lymph nodes were positive, and 13 per cent when three or more nodes were positive. Other factors useful in predicting prognosis are, to some extent, the level of lymph node metastasis in the neck, and the presence or absence of capsule penetration and soft tissue involvement. Those patients with metastasis to three or more lymph nodes had a five year survival of 13 per cent and belong to a high risk group. In this high risk group among those who died, the incidence of recurrence in the neck was 72 per cent, and the incidence of distant metastasis was 70 per cent. When autopsy was performed, more still were found to have distant metastasis, 75 to 80 per cent. Most of these high risk patients already have systemic dissemination of cancer at the time of their initial therapy; therefore, the addition of a systemic form of adjuvant therapy, such as chemotherapy and/or immunotherapy, is justified.