We examine how institutional factors influence the strategies entrepreneurial ventures use as they seek the knowledge they need to perform and compete. With a focus on economic and ecosystem development, we propose a framework of interrelations between two principal knowledge-search strategies, their interactions with varying levels of institutional development, and the joint effects on venture performance. We utilize a sample of 1,470 entrepreneurial ventures to examine two hypotheses. Results, based on hierarchical regression, distributed lag analyses, and several assumption and robustness checks show that knowledge-search strategy interrelations are complementary when institutional development is high but substitutive when institutional development is low. We execute a post hoc analysis using separate data sources to replicate these results and strengthen our findings. Finally, we discuss implications for entrepreneurial practitioners, policymakers, and scholars.