At present, there is significant momentum for developing and implementing computer-based patient records systems. It is essential that their development be guided by the functional requirements of the users and uses of patient records. Users can be grouped into seven categories: providers, patients, educators, researchers, payers, managers and reviewers, and licensing and accrediting agencies and professional associations. Uses of patient records include fostering continuity of care, supporting diagnosis and choice of therapy, assessing and managing health risks, documenting the services provided, maintaining accurate medical histories, billing and verifying payment, documenting professionals' experience, teaching students, preparing conferences and presentations, conducting research, formulating practice guidelines, and providing data to support utilization review, quality assurance, accreditation, and licensure. Patient records can be classified as primary records used by professionals while providing health care services or secondary records derived from primary records to aid nonclinical users. Protecting the confidentiality of patient information will restrict access to primary records for some users and should prevent inclusion of sensitive data in secondary records. The design features to be incorporated into computer-based record systems should expand the record's function from that of a simple device for documenting events into a powerful tool for providing and managing care.