Practical applications for using computers in everyday medical practice have not kept pace with the technical developments that now make this tool available to the pediatric practitioner. A modular approach to user-developed applications software is presented as a model for computerizing the pediatric office. Benefits have included lower cost, greater data reliability and validity, standardization of office and medical procedures, and automation of jobs formerly requiring much personnel time. Some patient services have improved, and other new services have become possible, through the application of computer software designed in accordance with our practice philosophy.