Background Adenoid cystic carcinoma (ACC) is the second most common tracheal tumor, but its optimal treatment strategy is still controversial. Methods To further elucidate the impact of treatment on disease-free survival (DFS) and overall survival (OS), we retrospectively investigated different treatment modalities and outcomes of 56 patients with primary ACC of the trachea treated at four hospitals in Sichuan Province of China from 1995 to 2012. Results 52 patients were included in the analysis. 4 patients with unresectable tumors were treated primarily with radiotherapy (RT) alone. 11 of 48 patients who received surgery as primary therapy obtained complete resection without adjuvant therapy. 24 of 37 patients who had incomplete resection (R1, R2) received postoperative RT while 13 patients were treated without postoperative RT. Postoperative chemotherapy (CT) was used in 12 patients with postoperative RT. No significant difference was shown in DFS (p = 0.683) and OS (p = 0.829) between patients with complete resection and those with incomplete resection. Postoperative RT for patients with incomplete resection was associated with improved DFS (92 vs. 62 months, p = 0.027) and OS (125 vs. 78 months, p = 0.004). Postoperative chemotherapy (CT) following RT did not have a significant impact on DFS (p = 0.390) or OS (p = 0.646) in patients with positive margin. Conclusion These observations suggest that postoperative RT should probably be recommended for patients with incomplete resection. Postoperative CT following RT in patients with incomplete resection did not seem to produce an additional survival benefit.