In this paper the authors retrospectively review various parameters which influenced local control and survival in a series of 76 patients with Tis or T1 glottic carcinoma. All the patients (89% smokers) received radical irradiation with two oblique anterior isocentric fields (45-315 degrees), with a Cobalt unit, 5 x 5 or 6 x 6, using compensator wedges; 2 Gy were given per fraction, up to 60-66 Gy at the minimum reference isodose. The mean total dose to ICRU reference point was 68 Gy (range: 63-72 Gy). All patients achieved complete remission. Four patients only had a local recurrence and none had regional relapses. Few late side-effects were observed and among them only two grade I and one grade II, the latter requiring tracheotomy. Eight patients died of cardiovascular diseases and nine of secondary cancer. Two patients are alive with a secondary malignancy. The five-year overall survival rate is 77.5%, while NED survival is 93%; no differences in survival rates were found according to T stage, grading, field size, treatment time and total dose delivered. With reference to the current literature, the authors conclude that: a) radiotherapy permits very good local control; b) lymph nodes should not be irradiated; c) very high doses do not improve local control, but only increase late side-effects; d) the role of biologic dose inhomogeneity and overall treatment time remain to be investigated.