To evaluate the therapeutic results obtained with (192)Ir low-dose-rate interstitial brachytherapy in T2N0 mobile tongue carcinoma. Between December 1979 and January 1998, 279 patients with T2N0 mobile tongue carcinoma were treated by exclusive low-dose-rate brachytherapy, with or without neck dissection. (192)Ir brachytherapy was performed according to the "Paris system" with a median total dose of 60 Gy (median dose rate, 0.5 Gy/h). Overall survival was 74.3% and 46.6% at 2 and 5 years. Local control was 79.1% at 2 years and regional control, respectively, 75.9% and 69.5% at 2 and 5 years (Kaplan-Meier method). Systematic dissection revealed 44.6% occult node metastases, and histologic lymph node involvement was identified as the main significant factor for survival. Complication rate was 16.5% (Grade 3, 2.9%). Half of the patients presented previous and/or successive malignant tumor (ear-nose-throat, esophagus, or bronchus). Exclusive low-dose-rate brachytherapy is an effective treatment for T2 tongue carcinoma. Regional control and survival are excellent in patients undergoing systematic neck dissection, which is mandatory in our experience because of a high rate of occult lymph node metastases.