"The popularity of executive coaching has increased dramatically in both the practitioner world and academia during the past decade. However, evaluating the effectiveness of coaching has lagged behind. Executive coaching is a multidisciplinary practice, and professionals from many different scholarly backgrounds provide coaching services. The paucity of empirical research may be attributed to the lack of a consensus among these divergent professionals regarding whether and how to evaluate the effectiveness of coaching. In this article, we conducted a meta-analysis of the empirical research as well as reviewed the retrospective studies evaluating coaching effectiveness. Subsequently, we discussed six areas that impact the way researchers evaluate coaching effectiveness and the conclusions they may draw from their studies. Although the Return On Investment (ROI) index provides a straightforward, overall measure of effectiveness, its veracity and usefulness is questioned. It is hoped that the clarification of these areas will help guide the future of coaching evaluation research and practice."