A retrospective analysis was performed to assess the relationship between the treatment modalities and treatment results in patients with adenoid cystic carcinoma of the maxillary sinus. From Feb. 1977 to March 1994, 10 patients with the disease were treated at the Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine. Six men and 4 women were presented with median age of 57 years. According to AJCC TNM system, all patients except one had advanced T3 and T4 disease. Only one patient had the regional metastasis to lymph node but none of them had hematogenous metastasis on initial admission. One patient(Group 1) was treated with surgery alone, 3 patients(Group 2) were treated with definitive radiotherapy and 6 patients(Group 3) were treated with combination of surgery and radiotherapy. One patient who was treated with surgery alone had experienced a locoregional recurrence 9 months later and 3 patients who were treated with radiation therapy alone had PRs(partial response) followed by the subsequent progression of the local disease. Whereas all patients who were treated with combination of surgery and radiation therapy had CRs(complete response). Among them, only one patient was recurred in the primary site, who was salvaged by reoperation and reirradiation therapy. In conclusion, combination of surgery and radiotherapy resulted in the best treatment modality for adenoid cystic carcinoma of the maxillary sinus. Improved radiotherapy technique and development of multimodality treatment are needed to improve the local control and the survival rate in patients with advanced adenoid cystic carcinoma of the maxillary sinus.