Clinical and histologic studies on the risk factors for the postoperative local recurrence of tongue carcinoma were analyzed in 51 patients. Postoperative local recurrence occurred in 12 (23.5%), with almost all developing within the first 12 months after surgery. A comparison of patients with and without recurrence indicated that the risk factors for recurrence were 1) endophytic tumor growth, 2) grade 4 pattern of histologic invasion, and 3) tumor within 5 mm of the surgical margin (especially the deep margin). All T1 tumors were less than 5 mm deep, indicating that it is reasonable for partial glossectomy to be performed in patients with T1 carcinoma. However, for T2 through T4 carcinoma it seems that more extensive surgery should be performed because of the variability in depth of tumor invasion. The 5-year survival rate of the patients with recurrence was 45% and that of patients without recurrence was 73.7% (P < .01). The overall prognosis of tongue carcinoma should improve when surgeons take a more prudent attitude to the treatment of patients with these risk factors.