How can entrepreneurs improve knowledge transfer when working with large firms in open innovation relationships? This research explains how and why the relationship between knowledge transfer and innovation in open innovation contexts can be optimally structured. We explore a set of propositions using three qualitative studies with relevant stakeholders. Study 1 explored knowledge transfer in open innovation relationships between Corporate Venture Capital units and the startups in which they took equity stakes. Study 2 explored knowledge transfer in open innovation relationships between corporate R&D centers in large corporations and innovation hubs that existed away from the main company's structure and physical location, providing insights for entrepreneurs on the dynamics "behind the scenes" of corporate-sponsored innovation hubs or incubators they might work with. Study 3 explored knowledge transfer in open innovation relationships between a large company innovation center and startups they worked with and in many cases, incubated. Our findings offer enhanced theoretical explanations for open innovation outcomes and make specific recommendations for entrepreneurs and large firms that sponsor open innovation with the startups with whom they work.