Striated muscle tumors involving the nasal accessory sinuses apparently are extremely rare. Because of this it seems worth while to report a case of extensive rhabdomyosarcoma of the maxillary antrum. A survival period of seven years after treatment is especially gratifying. Regarding tumors of striated muscle, as with many rare and unusual tumors, the literature seems confusing, especially in the matter of prognosis. Jönsson1 considered rhabdomyosarcoma the most malignant and radioresistant of all the sarcomas of soft parts. Murphy, Dockerty and Broders2 pointed out that myoblastomas, particularly the uniform type, are in general slowly growing and clinically benign. They presented evidence that the polymorphous myoblastomas are more malignant histologically than clinically but that in general they tend to shade into rhabdomyosarcomas. Stout,3 too, pointed out that there was a difference between granular cell myoblastoma and the genuine rhabdomyosarcoma. Thus discrepancies may be due to differences in opinion in the classification