Purpose: It is a great challenge to deliver the concept of medical professionalism to medical novices. Based on student reflections from the 2-credit course "Introduction to Global Health" in 2013, we further implemented service learning to the course in 2015 and analyzed if Introduction to Global Health raised self-awareness of medical novices towards professionalism and service learning changed their perception of medical professionalism. Methods: Three pedagogies (story-telling, situational discussions in small groups and reflections) were used in 2013-2015. Community service was implemented in 2015. Post-class surveys and student portfolio in 2013 were used to design three post-class surveys. The surveys were used to analyze if students recognized the hidden concepts related to three important components in medical professionalism: bioethics, personal attitudes, and human values. Results: In the course, students recognized two major bioethics principles, beneficence and justice; four important attitudinal characteristics, responsibility, accountability, self-improvement and dedication; and three attributes of human values, Altruism, Compassion and Empathy. Community service significantly changed the ranked score of Dedication and Dedication related to attitudes. Conclusions: Students were aware of key features in bioethics, attitudes, and human values related to medical professionalism. Service learning changed their perception on the important features of attitude but those of personal values. Our study suggests that Introducing Global Health to medical novices is a plausible way to raise their awareness of medical professionalism and service learning offers an effective approach to alter learners' attitudes.