Background: Cancers of the maxillary sinuses are not common and are the most difficult head and neck malignancies in which to make an early diagnosis. Objectives: This reports was conducted to evaluated the efficacy of combination therapy and the relationship between the treatment modalities and their outcome of maxillary sinus cancers. Materials and Methods: We retrospectively analyzed a clinical datas of 46 patients who were treated at the department of Otolaryngology-Head and Neck Surgery. The Catholic University of Korea over 10 years between 1987 and 1996. Results: According to AJCC TNM system, 35 patients presented with $T_4$, 10 with $T_3$, one with T1. Two patients were treated with radiotherapy alone, 4 patients with chemotherapy alone, 17 patients with radiotherapy and chemotherapy, 23 patients with combination of surgery, radiotherapy and chemotherapy. The overall 5 years survival rate for combination therapy group were 57%, but 23 patients treated with the other treatment modalities all died within 2 years except two cases with chemotherapy and radiotherapy or radiotherapy alone. There was a statistical trend for better survival and local control in those patients treated with combination therapy than others(p<0.05). Conclusion: The results of this study suggest that it may be possible to acheive better results with aggressive combination treatment including surgery in advanced cases and to avoid orbital excentration in patients with orbital invasion.