This study focusses on the role of trust in knowledge sharing within the context of virtual communities of practice. Trust is widely accepted as an important enabler of knowledge management (KM) processes. We conceptualise trust across three dimensions, namely: competence, integrity and benevolence; we test hypotheses as to the effect of these facets of trust on knowledge sharing by surveying an intra-organisational global virtual community of practitioners. The results indicate that all three dimensions of trust are positively related to knowledge-sharing behaviour. Trust based on the perceived integrity of the community was found to be the strongest predictor of knowledge-sharing behaviour. Our findings suggest that the dimensions of trust buttress each other; although they are theoretically distinct, they appear to be empirically inseparable. We propose that in order for knowledge sharing to be enabled, trust must concurrently exist in all three dimensions. Implication to organisations in their recruitment policy is to include competence, integrity and benevolence in their sought-for attributes of new employees. KM practitioners also have to encourage these attributes in existing employees, who are potential members of on-line communities of practice. Knowledge sharing itself was conceptualised with three components – quantity (frequency), quality (usefulness or value) and focus (the degree to which an individual feels that they engage in knowledge sharing). Of the three components, focus exhibits the most significant relationship with trust factors. This finding makes knowledge sharing less tangible than perhaps would be expected. It suggests that establishing whether knowledge has been shared is more than counting the frequency or trying to evaluate the usefulness of the shared knowledge. These aspects are important especially to management, but to the individual who shares knowledge, her feelings of having shared knowledge appear to be more important. With the current understanding that knowledge sharing is more of a human activity than technology, it is important that any information system should be assistive in boosting users’ confidence that they are indeed sharing knowledge. If the systems do not re-enforce the users’ knowledge-sharing orientation, knowledge sharing may be discouraged. Notwithstanding the point made about knowledge-sharing focus, it is necessary to take into consideration all the components of knowledge sharing to fully capture the concept. This was well indicated when the combined variable of all (rather than individual) knowledge-sharing items had the strongest correlation with trust factors.