Despite the fact that online communities (OCs) enjoy a growing number of members, their success is regularly impaired by infringements of user trust by either the community operator or other users. Since previous research studies have focused their investigation of the effects of single IT factors on user trust and participation in OCs, the field lacks an integrative view on how a comprehensive set of IT factors affect trust and participation from a user perspective. This study aimed to address this limitation in the IS literature by conducting an online-survey among 364 members of general-interest OCs. The results show that the four clusters of IT factors (usability, transparency, quality assured content, and security/privacy) investigated in this study vary in their impact on trust factors and participation. Interestingly, usability was the sole IT factor to significantly influence both trust and participation. While transparency had only a significant effect on trust variables, quality-assured content and security/privacy-related IT factors were significantly related only to participation. Our findings offer a variety of theoretical and practical contributions that shed light on the design of online communities and on strategies that can be used to attract new users by investing money in appropriate IT mechanisms.