PURPOSE: This study was conducted to exam the effect of a biomedical ethics education program on the consciousness of biomedical ethics, moral sensitivity and critical thinking disposition in nursing students. METHOD: A quasi-experimental research design and repeated measured ANOVA were used. The participants were divided into an experimental group (n=148) and a control group (n=169). Each group underwent freshman university nursing training in two major cities. The mean age was 21.3 years and the time of providing the biomedical ethics education program was 15 hours for 15 weeks. The experimental group was provided biomedical ethics education during the semester; the control group was not provided any biomedical ethics education. RESULTS: The consciousness of biomedical ethics was increased significantly in the experimental group (t=-4.724, p<.001). Moral sensitivity was increased significantly in the experimental group (t=-2.021, p<.004). Critical thinking disposition was increased significantly in the experimental group (t=-5.775, p×.001). CONCLUSION: The results of the study show that providing biomedical ethics education to nursing students is an effective method to increase the consciousness of biomedical ethics, moral sensitivity and critical thinking disposition.