Ethics has become an increasingly emphasized issue in recent years. Ethical decision-making is an action needed in both social and work life. One of the most critical issues in the professional life of accounting professionals is making ethical decisions. This study aimed to examine (i) the ethical decision-making levels of professional accountants and (ii) the impact of affective commitment, whistleblowing, and turnover intention on the ethical decision-making levels of accounting professionals. In this context, quantitative research was conducted with the participation of 147 professional accountants working in Sakarya. Frequency analysis, exploratory factor analysis, internal consistency test, descriptive statistics, independent samples T-Test, Hedge's g test, correlation, and multiple regression analysis were used to analyze the data. According to the findings, the ethical decision-making levels of professional accountants were pretty high. Ethical decision-making was positively associated with affective commitment and external whistleblowing. Female accountants' levels of ethical decision-making, external whistleblowing, and affective commitment to the organization were significantly higher than their male colleagues. In the multiple regression analysis, external whistleblowing and affective commitment positively affected ethical decision-making, while no action in whistleblowing had a negative effect. The research findings were discussed, and some suggestions were provided for further study in the field.