Applying D&M IS success model, the study integrates three web quality factors (web quality: system quality, information quality, and service quality) and online trust to explore the IS success model of health websites. A survey of 1076 users of five teaching hospitals’ websites was conducted to validate the proposed model. According to the statistical results, the proposed model fits very well for the samples. The findings also show that three web quality factors have all significantly positive effect on web usage and web satisfaction. In addition, this study also confirms that online trust is important antecedent of web outcomes. System quality, Information quality, service quality and online trust jointly have significantly positive effect on web usage and web satisfaction. This study emphasizes the importance of both technological and social psychological factors in the progress towards success health websites. By integrating online trust into the success model of health websites, the proposed model extends beyond traditional technology-based view of web systems, and can provide academics and practitioners with better assessment of web success.