Introduction: The aim of the present study was to investigate the predicting role of the big five personality traits in the four components of moral decision-making. Method: The population of this descriptive-correlation study included all the students in the University of Mazandaran. The participants were 384 students selected by stratified random sampling. In order to collect data, the Mini-IPIP, Ethical Sensitivity Scale, DIT-2, Moral Identity Questionnaire and the Moral Courage Scale were used. The data were analyzed by SPSS-24. Results: According to the results of this study, neuroticism was a negative significant predictor of moral identity and moral courage, extraversion was a negative significant predictor of moral identity, openness was a positive significant predictor of moral identity, agreeableness was a positive significant predictor of moral sensitivity and moral identity and conscientiousness were a positive significant predictor of moral identity, and moral courage. Conclusion: According to the results of the present study, it can be stated that different personality traits can predict different aspects of moral decision making.