The purpose of this study was to investigate the effect of the publishing of negative financial news caused by financial scandals on the level of ethical decision making in the field of accounting and finance. The study was applied, follow-up and semi-experimental research. According to the research objectives, a semi-experimental research project has been used including two experimental and control groups (each has 35 people) and data were collected during 2018 using questionnaires and interviews from accounting staff or financial managers from manufacturing companies. The result has shown that the frequency of negative news of scandal and accounting and financial violations reduce the level of ethical decision making of accountants. Because the admission of immoral behavior among those who were influenced by the negative news of the financial scandals was more than the other group that was not affected by the news. Also, the background of professional activities has been effective in improving the level of ethical decision making, while variables such as age, gender, and education have no effect on the level of ethical decision-making of accountants. Identifying and managing the factors that create heterogeneity in ethical decision making helps to improve the ethical decision making by accountants.