Retrospective analyses were done of 48 patients with early glottic cancer, 31 with T1NOMO and 17 with T2NOMO, who received radiation therapy from March 1979 to August 1984 at Seoul National University Hospital with the prescribed full dosage. The median follow-up period was 67 months (range: 34 months$~$126 months), and the percent follow-up for longer than five years was $85.4\%$ The five-year actuarial overall and recurrence-free survival rates of the whole patient group were $83.2\%;and;69.4\%$, respectively. The five-year actuarial overall and recurrence-free survival rates of the T1 group were $87.1\%;and;76.0\%$, and those of the T2 group were $76.5\%;and;58.2\%$, respectively. Possible causes of the failures to radiation therapy, the dose-response relationship, association with the second malignant tumors, and some recommendations for better treatment outcome are analyzed and discussed.