Purpose:To analyze the results of patients treated with perioperative interstitial brachytherapy (ISBT) in tongue carcinoma (TC).Material and methods: From April 2009 to May 2015, 43 squamous cell carcinoma consecutive patients diagnosed with TC were treated with limited partial glossectomy and perioperative ISBT, using high-dose-rate (HDR). Twentyseven patients were treated by brachytherapy (BT), and sixteen received BT as a complement to subsequent external beam radiotherapy (EBRT) after results of lymph node dissection. Median age was 66 years. Distribution by stage, included 10 patients stage I, 14 stage II, 10 stage III, and 9 stage IV. Eighteen patients had negative margins, nineteen margin involvement, and in six cases, the margin was < 5 mm.Results: With a median follow-up of 54 months, LC at 3 and 5 years was 87% and 84%, respectively. LC was 95% at five years in patients with clear margins, and 75% with involved margins. LC in N0 patients treated with BT was 83% at 5 years, and in patients N+ with posterior EBRT treatment, LC was 86%. By tumor size, we found one local relapse in 13 cases T1, in 5 of 27 patients T2 was found, and no local relapse T3 with LC of 87%, 70%, and 100% respectively at five years. Regional control (RC) was 81% at 3 and 5 years. We found a metastasis-free survival of 91% at 3-and 5-year. Twenty-three patients have died, 11 of them due to other causes, with overall survival of 56% at three years and 53% at five years.Conclusions: Combined treatment with conservative surgery and ISBT shows similar results to radical surgery or RT alone, allowing a more patient-tailored approach, with good organ function preservation and cosmetic outcomes.