Informal carers of people with Alzheimer's disease require access to high-quality information, which may be available through the Internet. Tools that have been developed to evaluate the contents of health-related web sites tend to be generic and not specific for diseases or patient groups. The aim of this study was to develop a tool that was specifically designed to evaluate web sites that provide information about Alzheimer's disease for informal carers of people with the disease. The tool was used to evaluate a sample of 15 web sites. The results were compared with those obtained using four generic tools in an earlier study. Several web sites attained high scores using the specific tool, although almost half of the 15 web sites achieved scores of less than 50%. There was a poor correlation between the rankings obtained using the specific tool compared with the generic tool. Web sites generally scored lower using the specific tool compared with one of the generic tools. Further work is required to develop and evaluate the Alzheimer's disease web site evaluation tool to help improve the quality of information available to carers through the Internet.