The purpose of this causal comparative study was to compare the Grit (Grit-S) and Resilience (RS-14) scores between two groups of non-traditional doctoral students in pursuit of their terminal degree at a university in the southwestern United States to determine if significant differences existed. The theoretical foundations for this study included Tinto's Theory of Student Retention, Grit Theory, and Resilience Theory. By comparing the self-reported scores of these constructs from students who have reached the dissertation-phase of their degree program to those who were in the first-year, this study sought to understand the role that Grit and/or Resilience might play in the retention, or attrition, of non-traditional doctoral students. Using the Mann-Whitney U test to compare the means of the two independent groups, this study concluded that no significant differences were demonstrated for either Grit (U[subscript Grit] = 42110.500, p = 0.121) or Resilience (U[subscript Resilience] = 44103.000, p = 0.515). Based on these results, this study provides no support for the hypotheses that either grit or resilience might have a role in the retention, or attrition, of non-traditional doctoral students in pursuit of their terminal degree. These findings emphasize the need for further study into the possible individual characteristics which can positively impact the successful pursuit of a doctoral degree. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]