Even though online communities enjoy a growing number of members, their success and popularity are regularly diminished by infringements of user trust. Consequently, community operators implement IT-based trust-promoting features to regain user trust. Not knowing if their efforts are effective, for community operators the question remains: how do trust-promoting IT-features contribute to user participation? In this paper, we present a content-analysis-based study that investigates the effect of trust-promoting IT-features. IT-features fall into four categories: usability, transparency, quality-assured content (QAC) and security/ privacy. The results show that usability, QAC, and security/ privacy strongly affect user participation. However, their implementation in online communities leaves a great deal of room for improvement. This work contributes to an understanding of trust-promoting IT-features and sheds some light on their efficiency. The findings have important implications for community operators, as we recommend that they invest in implementing usability, QAC, and security/ privacy IT-features to regain their users’ trust and increase user participation.