This research conducts four case studies of official English tourism websites, including Taiwan, Switzerland, Austria, and Germany-the latter three rank as the top three countries in the World Economic Forum's 2009 Travel and Tourism Competitiveness Report. The case studies are intended to carry out in-depth comparisons of international tourism websites. Research methods include heuristic evaluation, usability testing, and card sorting. Research subjects are composed of Taiwanese people and foreigners. Research results show that these four official tourism websites have similar performances in heuristic evaluation and usability testing, while there are slight differences in results of card sorting. The current classification and naming of items on the official English website of Taiwan Tourism Bureau are slightly different from the general usage on the other three websites, which is reflected on the one hand in the results of heuristic evaluation and, on the other hand, in the completion rate and time required to complete usability testing.