Purpose: This paper aims to identify predictors that affect business student perceptions on ethical decision-making. This paper also investigates how those predictors impact the decision-making related to ethical matters among Vietnamese business students. Design/methodology/approach: A survey was conducted to collect data for testing the hypotheses. Questionnaires were administered to 500 Vietnamese business students from four public and private universities. The independent t-test was applied to the usable sample to analyze and derive relationships. Findings: The empirical results showed that idealism and relativism significantly predict the perception of ethical decision-making. Idealism and relativism were found to influence high ethical decision-making significantly. Originality/value: The study contributes to the literature on ethical decision-making in a transitional economy. New findings and insights from the research serve as a foundation for future research with ethics and decision-making topics. The results offer some insights to business schools in improving their ethical teaching courses and to businesses in their recruitment.