For more than thirteen years, the Missouri Automated Radiology System has served as the information management system for the Department of Radiology at the University of Missouri-Columbia. MARS has evolved into a standalone modular system touching upon all aspects of radiology management. Written in MUMPS, the software system is flexible and has been consistently upgraded so that it is currently "state-of-the-art". Many management lessons are discussed here. Perhaps most important of all, the radiology information system has envolved in into an instrument of policy. Whoever controls the system controls the department. There still exists a tug of war between the advocates of the central computer system and the users of the standalone system. With the advent of the image management system, which clearly is in the domain of radiology, it is apparent that proper function of the department requires a marriage of the information management system and the image, management system. Therefore, it is imperative that these highly professional activities be based within the department of radiology.