This paper examines whether appealing to learners moral identity makes a significant contribution to improving their ethical decision making beyond traditional, rule-based teaching. In response to criticisms leveled at rule-based ethics teaching by alternative approaches, we identify moral identity theory and experiments in moral psychology as useful sources to draw on for the creation of a new, identity-based ethics teaching approach. We develop and apply a set of regular self-reflection focused writing tasks added to the traditional teaching program over a one-semester period, and assess the outcomes of an overall sample of 149 postgraduate business school students, who were randomly assigned to one of three conditions: exposure to both identity-based tasks and rule-based teaching, exposure to rule-based teaching only, and the control condition (i.e., no exposure to ethics teaching). Our findings show that, while the three groups reported the same level of ethical decision making at the beginning of the semester, at the end of the semester the students who were exposed to both identity-based and rule-based teaching reported higher level of ethical decision making compared to those who were only exposed to rule-based education. In addition, the students who received rule-based teaching reported higher ethical decision making compared to those in the control condition. These results suggest that a teaching approach which appeals to the learner s moral identity can act as an effective leverage point when complementing rule-based teaching. This simple approach should be widely adopted as common practice in graduate business schools.