OBJECTIVETo retrospectively analyze the results of treatment outcome by surgery combined with 125I brachytherapy and correlative factors of adenoid cystic carcinoma (ACC). METHODSIn the study, 75 patients with primary ACC of oral and maxillofacial region were treated by surgery combined with 125I seeds brachytherapy. Radical resection or subtotal resection was applied for the tumor. The brachytherapy treatment planning system was used to create implant plans with the prescribed dose of 60 Gy to 120 Gy. The 125I seeds were implanted intraoperatively or postoperatively. The regular follow-up was required. The Kaplan-Meier method was used to assess the tumor control rate and the patients' survival rates. Meanwhile, the Cox regression analysis was used to find out the prognostic factors. RESULTSLocal control rates at the end of 3 and 5 years were as follows: T1-T2, 92.2% and 82.0%; T3-T4, 82.6% and 82.6%; and overall, 90.0% and 78.8%. The disease-free survival rates were 74.9% and 54.3%, respectively. The overall