An undergraduate fraternity member's commitment to their organization and sense of belonging obtained through brotherhood may result in higher levels of growth and development, specifically positive mental health. Emphasis explored in the literature includes mental health and fraternity experience. Using the frameworks of Meyer and Allen's (1991) Three-Component Conceptualization, Edwards and Peccei's (2007) Organizational Identity, McCreary and Schutts (2015) Schema of Brotherhood, and Lutz et al. (1992) Positive Mental Health (PMH) scale, the researcher uses Dyad Strategies' secondary data of 10,538 fraternity member responses from year 2023 to explore what relationships, if any, exist between fraternity members affinity (affective, normative, and organizational identity) and sense of belonging (a component from Schema of Brotherhood) to reported PMH. Dyad's data was also used to compare how fraternity members PMH scores varied across institutions in nine regions of the United States and Canada. The researcher found a significant relationship between fraternity members affinity and sense of belonging to their PMH and discovered various significant differences among the nine regions. This researcher concludes the research study by discussing these results and providing suggestions for future research and advice for practitioners. [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.]