On the basis of data employed in radiation therapy with megavoltage X-radiation from the linear accelerator Philips SL 75/10 have been developed clearly arranged and practicable treatment schedules for the use of the radiotherapist. Application of a fixed focal dose, for instance 250 R per session, makes the number of days needed for irradiation easy to calculate. The possible field sizes are classified with regard to equivalent relative deviations at the class limits, and represented by a pattern of diaphragms. Thus, and by the use of constant focus-skin distance of 90 cm, well-arranged tables are obtained. Two-year experiences with the utilization of these schedules as well as the check-up by daily measurements and the necessary controls of operating conditions are summarized in diagrams.