Clinical supervision is often considered to be one of the important tasks in training psychotherapists. The present study investigated the relation between trainees’ attachment to their supervisors and trainees’ perceptions of their own counseling self-efficacy (CSE), as potentially moderated by trainee level of experience. Results indicated that trainees with greater avoidant attachment to their supervisors demonstrated lower levels of CSE. Although the results of the moderator analyses were not statistically significant, levels of avoidance significantly predicted levels of CSE even when controlling for level of experience, whereas levels of anxiety were not found to significantly predict levels of CSE. The study also found that individuals who reported greater levels of experience were more likely to report greater levels of CSE. The implications of the study are discussed, and recommendations for clinical supervision process are offered. (PsycINFO Database Record (c) 2018 APA, all rights reserved)