Appropriateness and adequacy of health information on the Internet varies. Given there is no validated instrument for web site evaluation focusing on elective general surgical procedures, our goal was to create a composite score as a web site quality rating system. The components of a composite score were developed through a literature review and included Agency for Healthcare Research and Quality guidelines of "Having Surgery? What You Need to Know" and previously published health-related web site scales. All criteria are given equal weight (0/1 scale). The composite score is reported as a percentage of a total possible 16 points. To pilot the rating scale, a web search for roux-en-y gastric bypass (RYGB) was used. Validation compared the composite score with an evaluation by surgeons. Mean composite score for 18 RYGB web sites was 48 per cent (range, 19% to 75%). Composite score validation used a cutoff value of 50 per cent. There was 100 per cent agreement (kappa = 1.0) between composite and surgeon scores. This is the first validated comprehensive composite score to evaluate the web site quality for patients undergoing elective surgery. This score shows promise in increasing efficiency of surgical practices by providing a way in which we can evaluate web sites and encourage our patients to become well informed by reading only high-quality web sites.