The records of 160 patients with squamous cell carcinoma of the tonsillar fossa treated from 1968 through 1979 were reviewed. Biologic behavior, local and regional findings, and other prognostic factors were evaluated. patients were treated by either radiation alone (112 patients), radiation followed by planned neck dissection (31 patients), surgery alone (11 patients), or surgery combined with radiation (6 patients). Analysis of the data supports the recommendation that radiation be used as treatment for T1, T2, and early T3 lesions, whereas surgery alone or combined with radiation is best employed for advanced T3 or T4 tumors. Primary tumor control rates with radiation as the initial modality were 100% for T1 lesions, 89% for T2, 68% for T3, and 24% for T4. In addition, the control of cervical metastases with radiation therapy for patients with neck disease staged N0 through N3b was excellent (95%). In instances where a planned neck dissection was done 5 weeks after radiation, the control of cancer in the neck was 100%. The incidence of distant metastases was 10% and was not affected by the selection of therapy. The 2- and 5-year determinate survival figures for 112 patients treated with radiation therapy alone was 67% and 48% respectively, while 31 patients treated with radiation therapy followed by neck dissection achieved survival rates of 70% (2 year) and 58% (5 year). The criteria for selection of treatment are discussed.