The purpose of this study was to investigate the influence of student organization membership on the development of leadership practices among traditional-aged undergraduate students. Specifically, the influence academic-related student organizations have on the leadership development of its student officers and members. This quantitative study explored the transformational leadership behavior of student officers and members of academic-related student organizations at a large research I public university in the mid-west. The student version of the Leadership Practices Inventory (LPI) was utilized to provide self-reported assessments of the leadership practices of the student organization officers, student organization members, and of students not involved in student organizations. Analysis was completed to determine the level of practice of the five leadership practices identified by the Student Leadership Practices Inventory and to compare these levels of practice between students involved in academic-related student organizations and students who were not involved in a student organization. The study documented a significant difference for all five leadership practices between students who served as academic student organization officers and students who were not involved in a student organization. The results for the comparison between students who were members of an academic student organization and students who were not involved in a student organization found no significant difference for all five leadership practices identified by the Student Leadership Practices Inventory. Analysis was also completed to determine any differences in leadership practice based upon sex. The majority of these comparisons showed no significant difference. However, there was a significant difference between student organization officers and students not involved in a student organization. Female student organization officers self-reported higher scores in the practices of Inspire a Vision, Challenge the Process, and Enable Others to Act. Male student organization officers self-reported higher scores in the practices of Model the Way, Inspire a Vision, and Challenge the Process. There were no significant differences within study groups. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]