Educators and practitioners often raise the question of whether business schools sufficiently prepare students to stay morally engaged when faced with ethical dilemmas in the workforce. Specifically, they criticize the theoretical nature of traditional in-class exercises for inhibiting students’ moral development. We investigate the impact working business mentors have on business student moral disengagement. We collected three waves of data from an 8-month formal mentoring program that matched business students with working mentors from the business community. We found that student protégé moral disengagement decreased during the mentoring program as a function of mentor ethical leadership skills, moral identity internalization, and moral awareness. Consequently, we recommend that mentoring programs pay close attention to these mentor characteristics to elevate business student moral reasoning and avoid unintended negative consequences. To guide mentoring programs in this endeavor, we provide specific recommendations for structuring a training program that focuses on improving mentor critical thinking, moral awareness, and ethical leadership.