The purpose of this retrospective study is to evaluate the efficacy of radiotherapy combined with superselective intra-arterial infusion therapy of cisplatin for locally advanced maxillary sinus cancer at single institution. We have evaluated 38 patients with locally advanced maxillary sinus cancer, who were treated with curative intent radiotherapy combined with superselective intra-arterial infusion therapy of cisplatin from 2002 to 2016. There were 31 males and 7 females. The median age was 67.5 years (range 47 to 87 years). Stage distribution was T2 in 1 case, T3 in 5 cases, T4a in 23 cases, and T4b in 9 cases. All patients have no nodal involvement. There were 36 patients who had squamous cell carcinomas, and 2 with undifferentiated carcinomas. Thirty-five patients received three-dimensional conventional radiotherapy, and the 3 most recent patients received intensity-modulated radiation therapy. We used 4 MV and/or 10 MV X-ray with or without electron beams. Median prescribed dose was 66 Gy (range 50 to 70 Gy) in 2 Gy/fraction. All patients did not receive either prophylactic neck irradiation or volume reduction surgery before radiotherapy. Superselective intra-arterial infusions of high-dose cisplatin was performed in 36 patients with simultaneous intra-venous infusions of thiosulfate to neutralize cisplatin toxicity, and 2 patients received selective intra-arterial infusion chemotherapy without sodium thiosulfate neutralization. All patients were treated with median 6 cycles (range 2 to 10 cycles) of intra-arterial infusion chemotherapy per week during radiotherapy. Systemic chemotherapy was also combined in 2 patients after the completion of radiotherapy. The median follow-up period was 38.9 months (range 3.6 to 178.3 months). The 5-year overall survival rate, disease-free survival rate, and local progression-free survival rate were 78.3% (T2-3/T4:100%/70.4%), 44.5% (T2-3/T4:83.3%/36.0%) and 58.3% (T2-3/T4:83.3%/53.7%), respectively. Although 13 patients had persistence of disease, delayed local failure occurred only in 2, regional recurrence in 3, and distant metastasis in 4. As salvage treatment, 9 patients underwent salvage surgery, and 2 patients underwent stereotactic radiotherapy. Although acute Grade 3 mucositis developed in 10 patients, no renal dysfunction occurred during the treatment. There were 9 late complications, including osteonecrosis (2 patients), carotid cavernous sinus fistula (1 patient), cateract (2 patients), blindness (4 patients) as late adverse reactions. Radiotherapy combined with superselective intra-arterial infusion therapy of cisplatin for maxillary sinus cancer appears to be efficient. However, further work is needed to decrease late complications.