The carcinoma of the maxillary sinus occupies about 0.25% of all human cancers. The radiations therapy for maxillary sinus hs not been practiced widely in this country. The authors treated a case of relatively advanced maxillary sinus cancer with combined radium and external irradiation with a succesful result. The clinical course and treatment are introduced and evaluated in detail. The authors believe that the carcinoma of the maxillary sinus is a curable disease even though it is relatively advanced one.