Leadership development is an essential strategic priority for organizations and this is most evident in the growing organizational costs spent on leadership development initiatives. This increase in financial spending on developing leaders has not, however, been accompanied by an equivalent increase in the level of satisfaction with the outcomes of these initiatives. In fact, many organizations point out substantial leadership deficit and complain that participating leaders are not equipped with the critical capabilities and skills they need in order to succeed in today’s turbulent reality. Some even assert that many leadership development programs have little impact and that perhaps the whole leadership development industry is failing. The enormous and widening mismatch between leadership development as it exists and what leaders actually need has been highlighted as a main reason for the dissatisfaction with, and in some cases perceived failure of, leadership development training. In this course, we review the various leadership development approaches used to supply organizations with a sustained pipeline of organizational leaders and analyze these approaches using the scientific research lens. More precisely, we shed light on these approaches’ contents and premises, and review the research evidence supporting, or revoking, their effectiveness. The course attempts to unfold why and when a leadership development initiative delivers on its promises.