Background: Internet travel purchases accounted for 10% of the travel industry revenue generated in 2001. To ensure that travelers remain healthy during excursions to developing countries, travel health information needs to be available at commercial travel websites. We evaluated the current availability of travel health information at these websites. Methods: The existence, adequacy and ease of access of the travel health information provided on commercial travel websites was assessed through a review of the top 25 airline and 20 discount travel websites. Each site was examined to determine whether it provided general information, such as jet lag, or international travel health information, such as malaria prophylaxis. We also assessed hyperlinks to external travel health information websites, such as the CDC, when provided. Results: Travel health information was not available at 20 (44%) commercial travel websites, including 36% of airline and 55% of the discount travel websites. Twenty-eight percent of airline websites contained general information only, 8% links only, and 28% general and international information. Travel health information available at discount travel websites included 10% general only, 30% link only, and 5% general and international information. On average, it took three clicks to access travel health information. Keywords clicked to access travel health information frequently did not obviously refer to health. Each of the six travel health website links provided accurate vaccine and travel health information. However, several links lacked disease-specific maps and details of disease risk (i.e. seasonal and regional variations of malaria risk). Conclusions: Travel health information on commercial travel websites may be the only data available to travelers purchasing online. The information currently provided is generally inadequate. Ideally, commercial travel websites would provide uniform information that is accurate and easily accessible. Internationally recognized organizations should consider establishing guidelines for the information provided on commercial travel websites.