Many observers have concluded that we have a crisis of professionalism in the practice of medicine. In this essay, the author identifies and discusses personal attributes and commitments important in the development and maintenance of physician professionalism: humility, servant leadership, self-awareness, kindness, altruism, attention to personal well-being, responsibility and concern for patient safety, lifelong learning, self-regulation, and honesty and integrity. Professionalism requires character, but character alone is not enough. We need others to help and encourage us. And in turn, as physician leaders, we help shape the culture of professionalism in our practice environment. Professionalism is not something we learn once, and no physician is perfectly professional at all times, in all circumstances. Professionalism is both a commitment and a skill—a competency—that we practice over a lifetime.