Mandatory preparticipation examinations (PPE) are labor intensive, offer little routine health maintenance and are poor predictors of future injury or illness. Our objective was to develop a new PPE for the Stanford University varsity athletes that improved both quality of primary and preventive care and physician time efficiency. This PPE is based on the annual submission, by each athlete, of a comprehensive medical history questionnaire that is then summarized in a two-page report for the examining physician. The questionnaire was developed through a search of MEDLINE from 1966 to 1997, review of PPE from 11 other institutions, and discussion with two experts from each of seven main content areas: medical and musculoskeletal history, eating, menstrual and sleep disorders, stress and health risk behaviors. Content validity was assessed by 10 sports medicine physicians and four epidemiologists. It was then programmed for the World Wide Web (http:// www.stanford.edu/dept/sportsmed/). The questionnaire demonstrated a 97 +/- 2% sensitivity in detecting positive responses requiring physician attention. Sixteen physicians administered the 1997/98 PPE; using the summary reports, 15 found improvement in their ability to provide overall medical care including health issues beyond clearance; 13 noted a decrease in time needed for each athlete exam. Over 90% of athletes who used the web site found it "easy" or "moderately easy" to access and complete. Initial assessment of this new PPE format shows good athlete compliance, improved exam efficiency and a strong increase in subjective physician satisfaction with the quality of screening and medical care provided. The data indicate a need for improvement of routine health maintenance in this population. The database offers opportunities to study trends, risk factors, and results of interventions.