We describe a computer-assisted data collection system developed for a multicenter cohort study of American Indian and Alaska Native people. The study computer-assisted participant evaluation system or SCAPES is built around a central database server that controls a small private network with touch screen workstations. SCAPES encompasses the self-administered questionnaires, the keyboard-based stations for interviewer-administered questionnaires, a system for inputting medical measurements, and administrative tasks such as data exporting, backup and management. Elements of SCAPES hardware/network design, data storage, programming language, software choices, questionnaire programming including the programming of questionnaires administered using audio computer-assisted self-interviewing (ACASI), and participant identification/data security system are presented. Unique features of SCAPES are that data are promptly made available to participants in the form of health feedback; data can be quickly summarized for tribes for health monitoring and planning at the community level; and data are available to study investigators for analyses and scientific evaluation.