Patients rely on the Internet for medical information. It is difficult to discern which resources are accurate or appropriate for patients. The purpose of this study was to develop a quality-assessment tool for health Internet Web sites and to apply this tool to assess the quality of burn scar management information on the Internet. Between September and December 2001, we prospectively evaluated all Web sites on the Internet search engine Yahoo! containing the headings 'burn scar management,' 'burn scar healing,' 'burn scar treatment,' and 'burn scar therapy.' The quality of each Web site's medical information was evaluated using our scoring system consisting of the following two components: quality and technical characteristics. The total score for each Web site was converted to a percent grade (eg, > or =80% = excellent, 70 to 79% = very good, 60 to 69% = good, 50 to 59% = fair, and <50% = poor). The Web sites were grouped into three categories: commercial (for profit), academic (university, hospital), and organizational (nonprofit). Of 88 Web sites evaluated, the majority 68 (77%) were commercial, 7 (8%) academic, and 13 (15%) organizational. Burn scar management information on the Internet was poor in the majority (79%) of commercial Web sites and was excellent, very good, or good in the majority of academic (86%) and organizational (77%) Web sites. Using our health information evaluation, we found that the majority of burn scar management information on the internet (77%) was of fair or poor quality. Academic and organizational Web sites had the best quality of burn scar management information. Additional testing of the developed tool will be needed to analyze the reproducibility of the results and their applicability in other medical domains. [ABSTRACT FROM AUTHOR]