The purpose of this collective case study is to examine the decisional ethic Christian school administrators employ when evaluating textbooks for adoption in Christian schools. The study affirms the truism that Christian schools ought to be decidedly Christian and focuses upon textbook adoption practices in Christian schools. A multisite, qualitative research design is employed to examine current practice of textbook adoption among a purposive sample of secondary schools within the Southeast region of the Association of Christian Schools International. The research questions address such administrative leadership factors as organizational values and learning objectives, textbook content criteria and features, and the decision-making processes employed in the textbook adoption task. This study examines the decisional ethic of the Christian school administrators by means of personal interviews, site visits, and other data gathering techniques. I incorporate two research-based data analysis methodologies involving within-case and across-case analysis and Analytical Hierarchical Processing as a decision-making model. The study found that textbook adoption is an ongoing, graded process across all academic fields. Administrators rely upon teachers and vertically- aligned adoption committees to inform this task. Administrators are also concerned with curricula alignment of textbooks with the organization's core values and learning objectives. Moreover, some administrators consult with peers outside of their current context to learn what textbooks are trending in other academic environments and geographic regions. This adoption factor, defined herein as lateral alignment, was not observed in the academic literature and may prove to be an addition to the field of research in the area of textbook adoption. [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.]