Why is continuing medical education (CME) important? Is the purpose of CME to demonstrate to participating physicians that their clinical practice meets standards of care? Is it to improve the quality of care? Should CME activities translate new knowledge into clinical practice? By definition, CME constitutes educational activities that serve to maintain, develop, or increase the knowledge, skills, performance, and the relationships a physician uses to provide services for patients, the public, or the profession.1 If CME is to be effective, specific educational resources are necessary to provide the adult learner with the knowledge and skills needed to update clinical practices that most impact patient care. This document provides an extensive systematic review of the literature to determine what evidence exists about the effectiveness of CME in both knowledge translation and patient care outcomes. This represents an important first step in critically analyzing the CME delivery process and CME efficacy, both critically important issues for the growing global emphasis on CME as a key factor driving maintenance of certification (MOC) and quality improvement.