Disturbances in interpersonal relationships are a core feature of personality disorders. Psychodynamic formulations in particular consider interpersonal problems as a central characteristic of personality pathology. Yet, despite the centrality of interpersonal issues in both theoretical conceptualizations and psychodynamic treatment approaches, relatively few studies have investigated the role and nature of interpersonal problems in psychodynamic treatments for personality pathology. This study set out to investigate in a sample of 44 personality-disordered patients whether hospitalization-based psychodynamic treatment was associated with changes in interpersonal problems, as measured with the Inventory of Interpersonal Problems, at the end of treatment and at three- and 12 month follow-up. In addition, this study investigated whether specific types of interpersonal problems were associated with symptomatic outcome assessed during treatment, at the end of treatment,and at three- and 12-month follow-up, and whether changes in interpersonal problems from baseline to the end of treatment were related to outcome at follow-up. Results showed that psychodynamic treatment was associated with significant improvements in interpersonal problems during treatment, and continuing improvement in interpersonal functioning after treatment. Yet, problems in the cold-vindictive and domineering domain were negatively related to outcome during, but specifically after, treatment, and also tended to show little improvement during treatment. Finally, the extent to which these interpersonal features and interpersonal problems in the overly nurturant and non-assertiveness domains changed during treatment, was associated with symptomatic improvement, particularly at follow-up. The implications of these findings for the psychodynamic treatment of personality-disordered patients are discussed.