Although there is a consensus that authentic leadership should be an essential component in educational leadership, no study to date has ever tried to find whether team-based simulations may promote authentic leadership. The purpose of this study was to identify whether principal trainees can develop authentic leadership through ethical decision making in team-based simulations of cases that they had experienced. Fifty principal trainees volunteered to participate in the study. A four-dimension model of authentic leadership was constructed, which may suggest that leadership programs should include teambased simulations in ethical contexts to develop the authentic leadership of the future.