This study investigated the effectiveness of a student leadership program at Yildiz Technical University (Turkey) based on the Kouzes and Posner (2018) leadership model. A quantitative quasi-experimental design with a pre-test and post-test control group demonstrated the effectiveness of the program. The analysis indicated a positive change for all five leadership practices, with three reaching statistical significance levels. Semi-structured interviews with students explored the two non-significant findings. The qualitative results suggested that leadership development programs need learning activities that apply to real-life situations and focusing on enhancing students' self-confidence as leaders.