Online Health Communities have become an increasingly popular information resource. Participants use them to seek health information, to seek support and to source advice regarding health challenges. The resulting lack of dependency on traditional health information channels has not only changed the way in which people source health information, but more importantly, the health information that they choose to trust and consequently act upon. Despite this fact, the factors that predict or inhibit users’ trust in online health communities remain unclear. This study seeks to contribute to our understanding of the factors that influence individuals trust in such communities. Data were collected from 410 Brazilian participants of several online health communities on Facebook. The research model was tested using partial least squares, and the results show support for two new predictors of trust in online health communities: Online Community Responsiveness and Community Support. Also, we found that Information Credibility and Propensity to Trust positively influence individual’s trust responses. These findings contribute both to the trust literature and to social media research knowledge. From a practitioner perspective, these findings can also serve as a guide for moderators and managers who wish to improve participants’ trust in their online health communities.