This IAMSE Manual offers a practical guide for defining, discussing, managing, and promoting professionalism in medical education. It addresses professionalism across the continuum—from undergraduate to graduate medical education and continuing professional development—through evidence-informed strategies, case studies, and institutional practices. Topics include curriculum design, ethical challenges, mentoring, conflict resolution, and infrastructure for addressing unprofessional behavior. With contributions from experienced educators and leaders, this volume provides actionable insights for fostering professional identity and humanistic values in academic medicine. It is suitable for faculty, administrators, and educators responsible for professionalism in medical education.