Modern society is heading toward a “projectified” model where individuals and companies repeatedly partner together in temporary projects. Yet, our understanding of how repeated interactions within temporary organizations influence project outcomes is still limited. We argue that repeated interactions reduce uncertainties and coordination costs but at the expense of resource diversity. In a longitudinal study of venture capital (VC) syndicates, spanning two technology-based industries, 33 years, and 36,155 VC investments, we find a curvilinear relationship (inverted U shape) between the extent of repeated interactions among VCs and the ventures’ likelihood to IPO, and that this relationship is moderated by two time related factors: the age of the start-up (i.e. project) and the age of the syndicate (i.e. temporary organization). We find that for older start-ups both the positive and negative effects of repeated interactions on performance are attenuated. Further, in older syndicates the positive effects of repeated interactions on syndicate performance are reduced, but the negative influence is not significantly moderated. We contribute to the temporary organization literature by showing the effect of repeated interactions on project performance, and by introducing two important time dimensions that shape this relationship.