To evaluate the effectiveness of hyperfractionation for T2 glottic cancer from a viewpoint of laryngeal preservation, we analyzed 21 patients (twice-a-day group) who were treated with hyperfractionation between 1992 and 1998 and compared the results with those of 27 patients (once-a-day group) treated with conventional once-a-day radiation between 1987 and 1992. In the twice-a-day group, radiation was performed with two fractions of 1.2 Gy/day up to a total dose of 72-74.4 Gy. In the once-a-day group, radiation was performed with a fraction of 2 Gy/day up to a total dose of 66 Gy. If radiation was ineffective at 40 Gy, it was stopped, and surgical treatment was carried out. Kaplan-Meier estimates were used for the analysis of the survival rate and laryngeal preservation rate, and the results were compared. In the once-a-day group, the 5-year survival rate was 92.3%. The 5-year laryngeal preservation rate was 51.8%, and it was 60.3% in 20 patients who had undergone full-dose radiation (once-a-day full-dose group). In the twice-a-day group, no major complication, such as laryngeal necrosis, was seen in any case, and the 5-year survival rate was 95.3%. The 5-year laryngeal preservation rate was 95.3%, and it was significantly better than that of both the once-a-day group and the once-a-day full-dose group. Hyperfractionation is considered to be useful for preserving the larynx for the treatment of T2 glottic cancer.