The current study investigated preliminarily therapists’ countertransference (CT) behavior and alliance quality as a function of therapist self-insight, a central CT management factor. Eight therapist-trainees were rated by a clinical supervisor on their degree of self-insight and then assigned to a high or low self-insight group. The groups were compared on therapist CT behavior, from both therapist and supervisor perspectives, and on patient-perceived alliance quality. Effect size estimates suggested that high self-insight therapists displayed more CT behaviors than low self-insight therapists (with small to medium effects), and that patients of high self-insight therapists reported higher alliance scores (with a medium effect). These findings, albeit preliminary and requiring replication with a larger sample, support the notion that self-insight plays a role in therapists’ use of CT reactions in the service of effective therapeutic interventions.