In 247 patients with squamous cell carcinoma of the maxillary sinus, the logistic multiple regression analyses were employed to identify prognostic factors. Among various factors evaluated, use of CT scans in treatment planning (p less than .004), age (p less than .009), location of the tumor (p less than .011), T-stage (p less than .017), and free set-up in radiotherapy (p less than .052) proved to be significant factors independently predictive of survival. The most significant factor in improving survival rate was the use of CT scans in treatment planning which was initiated in 1980. Against our prediction, intra-arterial 5-Fu infusion combined with surgery and radiation did not yield favorable result when compared with combined surgery and radiation. Radiation was combined with surgery, high dose radiation of 50 to 55 Gy delivered in 16 fractions over 4 weeks seemed to show better local control than other dose-fractionations.