Perfectionism in the counselor trainee has the potential to undermine counseling self-efficacy and relationships with client and supervisor (Arkowitz, 1990). Perfectionism is defined as “a predilection for setting extremely high standards and being displeased with anything less” (Webster’s II New College Dictionary, 1995, p. 816). In this study, 143 counselor trainees and 46 supervisors (46 supervisor-trainee dyads) completed surveys designed to assess the relationships between adaptive and maladaptive perfectionism and counseling self-efficacy, the working alliance between supervisor and trainee, as well as the working alliance between trainee and client. Trainee participants completed the Almost Perfect Scale – Revised (Slaney, Rice, Mobley, Trippi, & Ashby, 2001), the Self-Efficacy Inventory (Friedlander & Snyder, 1983), the Supervisory Working Alliance Inventory – Trainee Version (Efstation, Patton & Kardash, 1990) and the Working Alliance Inventory – Short Form Therapist Version (Horvath, 1991). Supervisor participants completed the Supervisory Working Alliance Inventory – Supervisor Version (Efstation, Patton & Kardash, 1990). Results indicated that maladaptive perfectionism was positively correlated with working alliance between trainee and client (r = -.261, p = .002) and positively correlated with the working alliance between supervisor and trainee (from the perspective of the supervisor, r = -.345, p = .019). Results also demonstrated evidence for counseling self-efficacy as a significant moderator between adaptive perfectionism and the supervisory working alliance (from the perspective of the trainee) and between maladaptive perfectionism and the supervisory working alliance (from the perspective of the supervisor). Supervisors should consider perfectionism in counselor trainees as this may affect counseling self-efficacy and working alliances between supervisor and trainee as well as between trainee and client.