Organizations increasingly use enterprise information technology (EIT) to improve effectiveness and efficiencies, and to maintain a competitive advantage. However, despite substantial research providing critical success factors (CSFs) leading to successful outcomes, a significant number of organizations view the EIT efforts as unsuccessful. In this realist synthesis, the researcher used the theoretical lens leadership behaviors, organizational change, and innovation to understand why and when leadership behaviors lead to successful EIT outcomes. Yukl, Gordon, and Taber's leadership behaviors and Dezdar and Sulaiman's CSFs taxonomies provided a framework to analyze 34 case studies to answer the primary research question: "What is the association between leadership behavior and an organization's EIT effort?" The findings suggested that the intervention of leadership behaviors triggers the mechanism of a follower response, which leads to follower behaviors and successful EIT outcomes when there is top management support, and leaders who are involved in the project have the knowledge, skills, and attributes to influence the CSFs. The practical implications are that an organization's executives should ensure that: (a) there is a shared understanding of the EIT effort among the organizational members must exist; (b) the members' needs are addressed, allowing them to accept change; (c) the EIT effort has authentic top management support; (d) the EIT effort is well managed; and (e) all members demonstrate authentic support behaviors for the EIT effort. The study is the first known study to use realist synthesis and case studies to link leadership behaviors, follower responses, and EIT outcomes. The results reconfirm the importance of top management support to change efforts and the linkage between leaders' knowledge, skills, and attributes, and the results. The number of leader--follower interactions is limited by the use of only 34 case studies. Future research should study other forms of EITs. Additionally, future efforts should assess other contextual environmental success factors for their influence on the leadership behaviors and follower response relationship. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]