The purpose of this study was to examine the ethical beliefs and preparation practices of high school principals when making decisions on the evaluation of teacher performance for retention and/or tenure. The participants consisted of a total of 10 high school principals, associate principals, and assistant principals who evaluate the performance of teachers for retention and/or tenure. The methodology consisted of participant observation, ethnographic interviews, and document analysis. The data were recorded and transcribed by the researcher and common themes were derived amongst the responses of the participants. The findings from the study indicated that principals are ethical agents who have received training in the evaluation of teacher performance. However, the training lacks root in ethics when making decisions on the evaluation of teacher performance. The results support more training in ethics in order for high school principals to make ethical decisions, prior to obtaining a leadership position and while currently employed in a leadership position. These findings provide insight to university preparation programs for school administration, individual state-mandated courses on teacher evaluations, and individual school districts and the training that is provided to principals on how to evaluate teacher performance. [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.]