Cognitive moral development theory posits that an individual’s cognition, emotion and judgment change as one moveS through stages of moral development. Age and work experience have been suggested as determinants of ethical ideology which in turn influences ethical behaviour. This study examined age and work experience as antecedents of ethical decision making of managers. Ethical judgment and ethical intention were used to measure ethical decision making. The findings indicate that older managers are not necessarily more ethical than younger managers. But the evidence demonstrated further that more experienced managers are more ethical than less experienced managers. It can be concluded that work experience rather than mere age is the real antecedent of ethical behaviour. Further analyses showed that this conclusion may be due to the evidence that more experienced managers are more idealistic and less relativistic than less experienced managers.