For the psychodynamic approach, being aware of and managing countertransference is a core therapeutic competency. Research has demonstrated the negative effect of unmanaged countertransference on the outcomes of all kinds of psychotherapy. In this study, we focused on the relationship between countertransference when measured by therapists and external observers and its impact on session quality. We analyzed 69 counseling sessions, held by 23 in-training psychotherapists with 23 patients. We used the Therapist Response Questionnaire and three external observers (who used the Countertransference Behavior Measure) to measure psychotherapists' countertransference. We rated the session impact perceived by patients and psychotherapists using the Session Evaluation Questionnaire and by patients through the Session Impact Scale. Psychotherapists' and observers' ratings of countertransference correlated though on different dimensions. These results indicate that comparing external and internal evaluations can help to understand various aspects of countertransference since they have different associations with the session outcome. From a methodological point of view, it is necessary to adopt various perspectives to investigate countertransference. Future research should confirm these results on a sample of experienced psychotherapists. (PsycInfo Database Record (c) 2021 APA, all rights reserved).