This study examines individual knowledge sharing in a coopetitive R&D alliance. R&D is increasingly carried out in an R&D alliance setting, where individuals share highly specialized tacit knowledge crossing firm boundaries. A particular challenging setting is the coopetitive R&D alliance, where partner firms partially compete and individuals may leak competitive knowledge. This setting has been studied on the level of the partner firm. We want to deepen insights by examining the individual level. Drawing on the motivation-opportunity-ability framework, we study the influence of individuals’ job experience (ability) on their performance in the alliance. We also examine effects of two- and three-way interactions between job experience, a central position in the social alliance network (opportunity) and intrinsic and extrinsic motivation. We find a positive association of job experience with individual performance, a positive interaction between job experience and extrinsic motivation and a positive three-way interaction between job experience, central network position and intrinsic motivation, and discuss the impact of these findings.