There are now millions of cancer-related pages on the Internet, so finding appropriate information about specific topics can be a real problem. Cancerindex.org aims to be a solution to this inconvenient, by providing users a filtered index of websites and related information within this area. The site is the Guide to Internet Resources for Cancer family of Web sites, and was established in 1996. It has over a thousand pages, and it is maintained on a voluntary / not-for-profit basis. Here Links are sorted into categories where possible annotation is provided to give the reader a brief description of each site or organization. As well as links, the site presents basic information about cancer-related topics. Also, the site aims to draw the reader’s attention to issues about cancer-related information on the Internet, especially those relating to the quality of information. Links are categorized according to their reference topic, including disease type, medical specialty, and country.