Leadership has been deemed, by some earlier scholars, to be less necessary in organizations that are knowledge-intensive. It has been assumed that because experts and professionals are driven largely by intrinsic motivation, extrinsic management and leadership factors are less important. We believe this assumption is wrong. Leaders have been shown in recent studies to have a considerable influence on organizational performance in universities, research institutes, hospitals and in high-skill sports settings. What matters, we argue, is the kind of leader. Experts and professionals need to be led by other experts and professionals, those who have a deep understanding of and high ability in the core-business of their organization. Our contribution will summarize the literature on the relationship between expert leaders and organizational performance, and then we will present a theory of expert leadership in a new model that outlines the possible transfer processes through which expert leaders generate better organizational performance.