CContrary to expectations, ethics research has shown that, accountants earn low ethical reasoning scores in the moral development tests, due to accountants focusing on agreeableness trait. However, ethical tests evaluate agreeableness trait up to the intermediate levels of the moral development model. The purpose of this study is to investigate the relationship between five personality traits and ethical judgments of accounting students compared with management students. The big five personality traits are conscientiousness, extraversion, agreeableness, neuroticism and openness to experience. I also investigate the relationship between gender and moral judgment. Using a questionnaire and answers provided by 386 accounting and business students, from five universities located in Tehran province, in 2018, results show, accounting students have a higher priority for agreeableness personality trait. But, there is no significant difference between the ethical judgments of accounting and business students. I find that those accounting students who do prefer agreeableness trait appear to have lower levels of moral judgment. While this relationship does not exist for the business students. This means that accounting students have different personality traits, influenced by their discipline, and therefore have different moral judgment. Also, for both groups, there is a positive significant relationship between conscientiousness and extroversion with moral judgment and the relationship between neuroticism and moral judgment is negative. Finally, the study of the relationship between gender and moral judgment showed that, according to theory of gender role in socialization, female students tend to have more moral judgments than males.