Social media such as We Chat provide new ways of communicating healthcare information and knowledge. Many healthcare institutions leverage We Chat public platform to disseminate healthcare knowledge in the hope of attracting public attention. It is critical for them to build a comprehensive understanding of the factors affecting WeChat users’ willingness to diffuse healthcare knowledge, an issue that has seldom been studied in the literature. This research aims to address this gap. Drawing on prior research on word-of-mouth, we develop a research model by integrating six factors regarding three key elements of healthcare knowledge communications: content (interestingness, usefulness, emotionality and positivity), source (source credibility) and channel (institution-based trust). The research model will be tested through a scenario-based online survey. This research is expected to contribute by (1) integrating factors that determine healthcare knowledge diffusion including the factors about content, source and channel, especially including institution-based trust as an important determinant, (2) examining the diffusion of healthcare knowledge and taking WeChat as the research context, and (3) using survey with subjective measurements to test a more comprehensive model. Potential practical implications are offered for healthcare organizations and practitioners.