The Council on Medical Student Education in Pediatrics continues its series on great clinical teachers, focusing on professionalism in practice. The Council on Medical Student Education in Pediatrics is in agreement with the Liaison Committee on Medical Education, Accreditation Council on Graduate Medical Education, and the CanMEDS Physician Competency Framework, that professionalism is essential to the practice of medicine, regardless of the level of training. Clinical teachers are in an excellent position to promote and assess professional behaviors in students but are often hesitant to address lapses in professionalism; however, addressing professionalism early is critical, as professional misbehavior in medical school is a major risk factor for subsequent censure by state medical boards.1 This article discusses tools and strategies for the assessment, remediation, and promotion of professionalism in medical students. Many practitioners say, “I know it when I see it,” but defining professionalism can be challenging. Professionalism is built on the principles of excellence, humanism, accountability, and altruism and is demonstrated through clinical competence, communication, and ethical understanding.2 Humanism and altruism encompass beneficence, respect, truthfulness, and placing the needs of the patient above one's own. Excellence and accountability include striving for high-quality patient care, making a commitment to lifelong learning, and exhibiting responsibility to duty. Professional maturity requires the development of these behaviors through deliberate practice so that they become the habits that define a good physician. Evaluating professionalism is the responsibility of every clinical teacher. Assessable components include adherence to ethical practice principles, effective interactions with patients and the people who are important to these patients, effective interactions with individuals within the health care system, reliability and accountability, and commitment to improvement.3 The development of professionalism in medical … Address correspondence to April O. Buchanan, MD, Department of Pediatrics, University of South Carolina School of Medicine, Greenville Hospital System University Medical Center, 701 Grove Rd, 4th Floor Balcony Suites, Greenville, SC 29605. E-mail: abuchanan{at}ghs.org