This chapter reviews the evidence of the development of ethical decision-making competencies of medical professionals. Selected studies are reviewed that use a theoretical framework that has shown the most promise for providing evidence of character formation. The evidence suggests that entering professionals lack full capacity for functional processes that give rise to morality (sensitivity, reasoning, motivation and commitment, character and competence). Further, following professional education, considerable variations in these abilities persist. Whereas many perceive that role modeling is the most effective way to teach professionalism, there is no empirical evidence to support the role of modeling in professional development. The chapter concludes with suggestions for facilitating character development resistant to influence by negative role models or adverse moral milieu.