Although studies have identified a link between employee intrinsic motivation (IM) and creativity and between positive mood and creativity, some of this study has been equivocal and little research has included these variables in an integrative model. Drawing from several theories of IM, we address this gap by proposing that IM is a critical intervening mechanism in the relationship between positive mood and creativity, and team knowledge sharing affects the power of this mechanism. Research on field data from 120 R&D team members in 30 teams found that team-level knowledge sharing moderated the relationship between employees' positive mood and IM, and IM mediated the relationship between employees' positive mood and their creativity. Implications of our findings are discussed.