The purpose of this mixed-methods study was to examine factors that influence occupational therapy doctoral students' self-efficacy for the Doctoral Capstone Experience (DCE). Six doctoral students enrolled in an entry-level occupational therapy doctoral program at a private university were recruited to participate. Students completed a four-item self-efficacy rating scale prior to and several times throughout their DCE. Participants also participated in semi-structured phone interviews regarding their relationship with their Site Mentor after completing the DCE. Quantitative data was analyzed using descriptive statistics and Kruskal-Wallis H tests. The quantitative analysis determined that there were no significant differences in self-efficacy for students who had previous experience in a setting similar to their DCE setting compared to those without, for students who had previous experience with a population similar to the population at their DCE compared to those without, nor for students who were mentored by an occupational therapist compared to those who were not. Yet as a whole, there was a significant change in the mean self-efficacy rating score for participants pre- to post-DCE. Qualitative data was analyzed through individual case studies and coding for themes. Qualitative analysis resulted in six themes regarding the mentorship relationship and factors that influenced students' efficacy beliefs. Each theme is discussed in relation to the theoretical framework with supporting quotes from participants included. Limitations of the study, implications for Capstone Coordinators for effective administration of the Doctoral Capstone Experience, and implications for future research are shared. [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.]