This study compares the ethical decision-making processes of Turkish, Thai, and American businesspeople, considering perceived moral intensity (PMI), corporate ethical values (CEV), and perceived importance of ethics (PIE). PMI describes the ethical decision making at the individual level, CEV assesses the influences of the organization's ethical culture on the decisions of the individual, and PIE reveals what the businesspeople believe about the relationships among business, ethics, and long-run profitability. The survey respondents are professional marketers and businesspeople currently enrolled in or graduated from MBA programs in Turkey (n = 416), Thailand (n = 605), and US (n = 446). The ANOVA results reveal that American businesspeople are more likely to perceive the unethical marketing behaviors as more serious than their counterparts in Turkey and Thailand. American and Turkish organizations are found to have higher CEV than Thai organizations. On the other hand, Thai and American businesspeople perceived ethics to be more important for business success than Turkish businesspeople. The understanding of the differences and similarities in ethical perceptions of the businesspeople from various countries is valuable for a successful and harmonious working together when engaging in global marketing activities. This study is thus believed to be useful for people who plan to invest or manage businesses in these countries, and many of the implications are thought to be valuable in international business arena.