This paper develops a motivation-based perspective to explore how organisations resolve the social dilemma of knowledge sharing, and the ways in which different motivational mechanisms interact to foster knowledge sharing and creation in different organisational contexts. The core assumption is that the willingness of organisational members to engage in knowledge sharing can be viewed on a continuum from purely opportunistic behaviour regulated by extrinsic incentives to an apparently altruistic stance fostered by social norms and group identity. The analysis builds on a three-category taxonomy of motivation: adding ‘hedonic’ motivation to the traditional dichotomy of extrinsic and intrinsic motivation. Based on an analysis of empirical case studies in the literature, we argue that the interaction and mix of the three different motivators play a key role in regulating and translating potential into actual behaviour, and they underline the complex dynamics of knowledge sharing and creation in different organisational contexts.