Treatment goals in psychoanalytic psychotherapy often include changes in underlying psychological structures, rather than only symptom reduction. This study examines changes in the anaclitic-introjective personality configurations following psychoanalytic psychotherapy with young adults in relation to outcomes. Thirty-three patients were interviewed pretreatment and at termination using the Object Relations Inventory (ORI). Prototype Matching of Anaclitic-Introjective Personality Configuration (PMAI) was applied to the ORI material by two independent judges (intraclass correlation coefficient=0.73). The patients were classified pretreatment as predominately anaclitic (n=13) or introjective (n=20). Outcome measures included the Symptom Checklist-90-R (SCL-90) and Differentiation-Relatedness scale (D-R) pretreatment, at termination, at the 1.5-year and three-year follow-up. Both groups improved post-treatment in terms of symptoms and developmental levels of representations of self, mother, and father. No significant differences between the anaclitic and the introjective group were found in this respect, and could not be expected due to the low power (0.27). The anaclitic group showed better balance between relatedness and self-definition post-treatment, while this improvement was not significant in the introjective group. Further and larger studies are needed to draw more farreaching conclusions about the relations between changes in personality configurations over the course of treatment and the treatment efficacy. The clinical implications of this approach to underlying dynamic psychological structures are discussed.