In this article, we discuss the growth of international service learning in undergraduate medical education and tie it to a burgeoning interest among students and educators in global health justice. The process of experience, reflection, and action is the cornerstone of cultivating a sense of social justice among students. Finally, we examine both risks and benefits to international service learning for medical students. We define "service learning," distinguish it from service and volunteerism, and offer praxis as a manifestation of professionalism.