The relationship between gender and ethics has been extensively researched. However, previous studies have assumed that the gender–ethics association is constant; hence, scholars have seldom investigated factors potentially affecting the gender–ethics association. Thus, using managers as the research target, this study examined the relationship between gender and ethics and analyzed the moderating effect of cultural values on the gender–ethics association. The results showed that, compared with female managers, their male counterparts are more willing to justify business-related unethical behaviors such as bribery and tax evasion, and that the gender difference in ethics becomes more pronounced under the cultural dimensions of collectivism, humane orientation, performance orientation, and gender egalitarianism. This study used data obtained through surveying 2,754 managers in 27 nations.