Despite research demonstrating the effects of hostile school climates on the academic achievements of minority sexual and gender identity (MSGI) youth, little attention is paid to preparing future teachers to work with this diverse student population. Given the importance of making learning environments safe and welcoming for all students, this study utilized mixed methodology to examine the role sexual and gender diversity played in one teacher preparation program. Questionnaires and interviews gathered data about pre-service teachers' and teacher educators' factual knowledge, professional commitment, and perceptions of preparedness concerning students who identify as sexual or gender minorities. The findings suggest the teacher preparation program addressed sexual and gender diversity at an inconsistent and superficial level. Pre-service teachers were interested in exploring these topics further, contrary to their teacher educators' perspectives that discussions about minority sexual and gender diversity are irrelevant outside of diversity courses. Implications are offered and future research encouraged. [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.]