This study used a quasi-experimental design to examine whether exposure to moral development theory and dilemma discussion in the asynchronous online learning environment resulted in significant gains in principled moral reasoning (DIT N2-scores) of undergraduate elementary and secondary education students. Participants were undergraduate students (N = 106) enrolled in 4 sections of an online education course at a Western Land Grant university. Results show significant increases in mean DIT N2-scores (p < 0.01) between overall subject pre and post test scores. Results provide evidence that education undergraduates show significant gains in moral reasoning when exposed to moral development theory and dilemma discussion in the asynchronous online learning environment.