Adequate treatment for carcinomas of the paranasal sinuses and nasal cavity demands a thorough evaluation of the site of origin and routes of spread of the tumor. Roentgenographic examination is the most accurate clinical procedure for obtaining this information. Detailed roentgenographic examinations are required in order to give the maximal amount of information with respect to the total extent of tumor involvement. Since these lesions tend to remain localized. the problem is principally one of local control of the disease. Failure to achieve local control has been seen to reflect an initial underestimation of the extent of disease or curtailment in the radicality of the treatment technique in an effort to preserve vision or avoid the risk of complications. In some cases, failure may be due merely to the fact that the disease is so massive that only palliation can be attempted.