In this study associations between alexithymia, interpersonal problems and cognitivestructural aspects of internal interpersonal representations were examined. Alexithymia was measured using the Structured Interview for Alexithymia (TSIA) and the Toronto Alexithymia Scale (TAS-20). To measure interpersonal problems, dominance and affiliation dimensions scores of the Inventory of Interpersonal Problems (IIP-64) were used and cognitive-structural characteristics of interpersonal representations were measured using the Social Cognition and Object Relations Scale (SCORS). As hypothesized, alexithymia was related to cold and withdrawn, but not to dominant or submissive, interpersonal functioning.In terms of the SCORS, alexithymia was negatively related to complexity of interpersonal representations, both in TAT and in interview narratives, indicating a link between alexithymia and mentalization. However, alexithymia was only related to the dimension of social causality when this dimension was scored on TAT narratives. Overall the TSIA provides the most consistent and stable results after controlling for negative affectivity.