The heterogeneity of glottic carcinoma results in variable loco-regional control probabilities from 40 to 80%. These widely different results may be due to two prognostic parameters of the tumor: the mobility of the vocal cord and the volume of the tumor. On the other hand radiation dose and technique may influence the treatment results. Stringent work-up has been prospectively undertaken in 156 patients with Stage II glottic carcinoma since 1974 through 1983 in the Academic Hospital of the Free University in Amsterdam. Several subgroups were defined from the beginning to indicate one or both of these prognostic factors. All were treated with a high quality accurate radiation therapy program delivering high dose to all patients with worse prognostic factors and even higher dosages to voluminous tumors with impaired mobility of a cord or slowly regressing tumors. The latter was individually judged for each patient towards the end of the treatment period. The loco-regional control probability of around 80% for all the subgroups irrespective of the prognostic factors indicate that the heterogeneity of Stage II glottic cancer may be influenced by high dosages of quality controlled radiotherapy. Thus results hitherto reported in literature may be further improved by the dose-schedules outlined here.