Museums and their websites are an important component in the promotion of accessible tourism. However, some problems related to web accessibility may raise great barriers to the practice of tourism by people with disabilities. This study evaluates the level of website accessibility of museums located in Portugal, as it illustrates the importance of information being presented in an accessible way. A sample of 575 websites was analysed based on Web Content Accessibility Guidelines (WCAG) 2.0, using an automatic web diagnostic tool (AccessMonitor). This analysis was performed considering the A, AA, and AAA conformance levels of WCAG. Currently the state of web accessibility levels is medium, and there are still constraints that make information gathering difficult for visitors with disabilities. After the barriers are identified, proposals to design more accessible websites are presented. These proposals contribute to making museums’ online information accessible to all people, independently of their needs and functional limitations.