We present a retrospective study of 551 patients treated with conservative surgery for glottic carcinoma at the Gregorio Marañón Hospital between 1962 and 1996. In all, 12% of cases were locally advanced carcinomas. In early-stage carcinomas there were no statistical differences in 5-year survival between those treated by endoscopic laser resection, vertical hemilaryngectomy and radiotherapy. However, tumor recurrence after primary radiotherapy was higher (27%) than with conservative surgery (12%), while the voice preservation rate was significantly higher with surgery (83%) than with radiotherapy (72%). With locally advanced cancer, irradiated patients (to 60 Gy) had a 50% probability of recurrence with a very low chance for salvage by total laryngectomy (5-year survival rate, 38.5%). In contrast, partial laryngectomy could be performed on carefully selected patients, and the results for these patients were comparable to those for smaller lesions (with a 5-year survival rate of 81%).