Much research has been done concerning Web service quality of travel-related businesses, nevertheless, there is a lack of research comparing Web service quality between online travel agencies and online travel suppliers. Therefore, the aim of this study is to: (1) identify the underlying dimensions of Web service quality between online travel agencies and online travel suppliers; and (2) compare the magnitude of Web service quality dimensions between online travel agencies and online travel suppliers in explaining the overall level of customer satisfaction. The results of this study will provide meaningful implications to operators and marketers of both online travel agencies and online travel suppliers.