The influence of ethical courses in the higher education of accountants on business decision- making is the topic of this thesis. The aim of the thesis was to find out if there is a difference between students in their knowledge of business ethics and ethical thinking of students as future professional accountants, considering whether or not they have acquired ethical knowledge through higher education. The subject of the work is the breakdown of the determinants that influence decisions made by professional accountants that are ethical or contrary to ethical principles. Also, one of the problems of the work is whether the cause of ethical or unethical behavior is not having knowledge of business ethics. The problem of lack of education on business ethics can greatly affect the difficulty of performing the work of professional accountants in future business situations. Adequate education of students as future accountants in terms of ethics enables fair, truthful and honest performance of accounting activities with the application of the Accounting Act and the principles of the Code of Ethics for professional accountants. The subject of morality and science dealing with the study of ethics is also theoretically elaborated in the thesis. On the basis of the conducted Chi-square tests, it was concluded that students will not behave differently in hypothetical situations of making business decisions, and that there is no difference in opinions among students about the representation of ethics at the faculty depending on whether or not they took a business ethics course. Also, it was concluded to the conclusion that students believe that attending courses in business ethics greatly affects correct behavior and the ability to make correct business decisions.