This study aimed to explore supervisee and supervisor experiences of relational depth (RD) within the supervisory relationship and its association with supervisee level of counselor self-efficacy (CSE). Participants in the study were master's level counseling students and their doctoral supervisors in a practicum course. A total of 52 supervisees (aged 22-57; 19.2% male, 80.8% female) and 18 supervisors (aged 25-46; 16.7% male, 83.3% female) participated in the study. Results demonstrated that supervisee perception of the relationship explained approximately 15% of the variance in supervisee CSE. Specifically, supervisee perception of supervisory working alliance (SWA; [beta] = 0.406, r[subscript s][superscript 2] = 0.997, p = 0.025) was found to be a significant predictor of CSE while supervisee RD was not a significant unique predictor ([beta] = -0.033, r[subscript s][superscript 2] = 0.370, p = 0.850), with most of the variance explained by RD being shared with SWA. Results also demonstrated that the supervisor perception of the relationship did not significantly explain variance in supervisee CSE. From these results, one may tentatively conclude that the supervisory relationship contributes to CSE, and that RD, as it is currently being measured, may not able to account for variance above or beyond that of the SWA. Extended results are described and summarized using text, tables, and figures. The study has practical and research implications for counselor educators, supervisors, and researchers in the RD field. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]