An abundance of ethical violations on the part of organizational leaders prompted the debate about the need for ethical leadership. Moreover, it spawned research interest in understanding the conditions that may prompt some leaders to pursue their own interests at the expense of their group, whereas others do not. This study explored whether the interplay between leader self-construal and leader power may explain this phenomenon. Across one laboratory experiment and one organizational survey, we showed that leader power interacted with leader self-construal in predicting leader self-serving behavior. Overall, our studies suggest that leader self-construal substantially shapes leader internal states and goals, and that the effects hereof on self-interested behavior are strengthened under conditions of high power.