Purpose: This study was performed to investigate the effects of a blended learning program on ethical values in undergraduate nursing students. Methods: This study was a one group pretest-posttest design. Seventy-one undergraduate nursing students who were taking a nursing ethics course at K University in S city were conveniently selected. The blended learning program was undertaken for 120 minutes one day weekly for 15 weeks. It consisted of case-based learning through an online method combined with problem-based learning offline. Scores for ethical value were measured using the ethical values scale. Results: The ethical values score increased significantly in the students after the blended learning (p=.004). Of the subgroup of ethical values human-life, relationship with collaborator, and nursing job scores increased significantly in students after the blended learning, respectively (p=.034; p<.001; p<.001), the score for area as relationship with nursing clients decreased significantly in the students after the blended learning (p<.001). Conclusion: The blended learning program was identified as an educational program which induces a positive effect on the development of ethical values in undergraduate nursing students, and in future it can be utilized in nursing ethics education.