This is a report of 413 consecutive cases of cancer of the larynx observed by me between January 1931 and January 1943. The main purpose is to discuss the advances in the radiation therapy of laryngeal cancer with special reference to concentration radiotherapy and to analyze its bearing on the present day treatment of this disease. It has been customary to separate cancer of the larynx into two main forms: extrinsic and intrinsic. There is, however, some confusion as to the exact definition of these terms, since they are used in the literature with different meanings depending on whether the particular classification is surgical or anatomic. According to the surgical classification, extrinsic carcinoma includes those arising from the aryepiglottic folds, pyriform fossae and postcricoid region as well as lesions arising within the laryngeal cavity which have spread outside the boundaries of the larynx. Obviously, lesions arising in the aryepiglottic folds,