The mainstay radical treatment of adenoid cystic carcinoma in the head and neck (HNACC) is surgery. The outcome of definite radiotherapy (RT) and surgery combined with postoperative radiotherapy (PORT) has not been properly compared due to the rarity of disease and imbalances of characteristics between patients receiving either treatment. The present study aims to compare outcomes of definitive RT versus surgery + PORT for HNACC using adjustment with propensity scores (PS). A retrospective review of medical records was performed in patients who underwent definitive RT (n=47) or surgery + PORT (n=145) for newly diagnosed nonmetastatic HNACC between January 1981 and December 2016. A median follow-up period was 4.9 years (range, 0.34 to 27.6 years). PS was estimated using factors including age, sex, T stage, N stage, radiotherapy techniques and primary sites. Propensity score (PS) matching and inverse probability of treatment weighting (IPTW) were used to estimate and compare survival outcomes. Five-year overall survival (OS), disease-free survival (DFS), locoregional control (LRC), distant metastasis-free survival (DMFS) of unmodified cohort were 75.7%, 31.4%, 66.3%, 34.2% (definitive RT) and 86.8%, 49.5%, 79.7%, 55.9% (surgery + PORT). These treatment outcomes were significantly different between two groups (p<0.05). In the PS-matched cohort, differences between the treatment outcomes were not significant. Five-year OS, DFS, LRC, DMFS of PS-matched cohort were 72.6%, 37.8%, 74.4%, 39.5% (definitive RT) and 89.3%, 48.2%, 79.0%, 52.1% (surgery + PORT). Also in the IPTW-adjusted cohort, the differences were not significant. Five-year OS, DFS, LRC, DMFS of IPTW-adjusted cohort were 77.9%, 51.7%, 81.9%, 53.6% (definitive RT) and 86.8%, 48.9%, 79.9%, 53.7% (surgery + PORT). Two analyses using PS showed there were no differences in treatment outcomes after balancing patient characteristics. Definitive RT would actually give better treatment results than those reported in previous studies. These results ultimately need be explored in a randomized trial.