Software has been developed that facilitates prospective computer entry of the clinical contents of a radiation oncology chart in a way that assists in retrospective analyses. This software, which has been operational since 1988, now contains detailed clinical information on over 500 patients treated since that time, and limited information on over 3000 children treated since 1970. The system has been programmed using the FoxPro database management system, and may be run on an IBM compatible or Macintosh personal computer either alone or in a networked environment. Information is transcribed as routine patient dictations that require no extra personnel for entry. Standard printouts are the conventional notes compatible with the existing paper chart. Exportation of patient records is facilitated by means of built-in facsimile. The software has been designed to generate detailed reports automatically, including the statuses of selected patients or groups, lists of those who are behind in follow-up, and reports of specific events (e.g., mucositis) that occur before, during, or after therapy using free-text searches. Complete reconstruction of the patient's clinical radiation oncology chart is also included. Other abilities include calculation of Kaplan-Meier survival, relapse-free survival, and local control rates, statistical comparison between survival curves, and radiation dose-response. Exportation of data to statistical and graphics packages is also possible. For pediatric patients, a program to predict stature loss has been incorporated. Use of this system can enhance one's ability not only to follow patients but also to monitor and report their outcome continually. With the need to report institutional experiences and increasing demands to monitor quality assurance, such a system can be of great benefit.