Virtual communities of practice (VCoPs) are increasingly recognized as a way to generate and assimilate organizational knowledge. VCoPs extend Wenger’s (1998) concept of community of practice to the virtual world, using technologies such as web forums, wikis, blogs, email, and social networking software. The success of a VCoP as a knowledge-sharing medium depends on active and useful contribution from members. Encouraging such contribution can be a challenge for managers given the informal, low-regulation environment of a VCoP. Conventional managerial controls and incentives become less significant in motivating contribution, and more intrinsic factors come to the fore. This research applies self-determination theory (SDT) (Ryan and Deci, 2000) to understand motivation to contribute knowledge in VCoPs. It hypothesizes that that the three basic human needs identified in self-determination theory—those for autonomy, competence, and relatedness—are motivators for contribution, and attempts to answer research questions formulated within this theoretical framework.