Evaluation of 63 patients undergoing primary radiation therapy for treatment of T1 and T2 glottic carcinomas was undertaken to evaluate the success of primary treatment and to identify factors which might influence recurrence or voice quality. Twelve patients (19%) recurred following radiation therapy, with ultimate salvage in 11, for a 3-year survival rate of 98%. Voice preservation was achieved in 83%. Continued smoking after radiation therapy was associated with significantly greater risk of recurrence. Stage of tumor and anterior commissure involvement were not associated with increased recurrences. Sixty-seven percent of patients who did not recur had good voice quality after treatment. Vocal fold stripping or excisional biopsy rather than limited biopsy for initial diagnosis, complications of treatment, and continued smoking after treatment were all significantly associated with an increased risk of poorer voice quality after treatment while bilateral vocal fold tumors were associated with risks that approached significance. Voice analysis of five patients revealed that objective changes in voice can be detected after radiation therapy in those with associated risk factors but may be normal in those without these risk factors.