According to interpersonal theory of personality, interpersonal behaviours can be causal and maintaining factors in emotional disorders. However, interpersonal styles have not yet been investigated in the treatment of obsessive compulsive disorder (OCD). The aim of the study was to investigate interpersonal style in OCD. The Inventory of Interpersonal Problems – Circumplex was used to assess the interpersonal styles of 101 outpatients with OCD treated with cognitive behavioural therapy (CBT). Patients with OCD had more interpersonal problems than the healthy control group. However, the OCD group presented with slightly fewer interpersonal problems than a further comparison group of psychiatric outpatients. Interpersonal style did not predict improvement in OCD symptoms. Following CBT for OCD, there were small to moderate improvements in interpersonal problems. These changes remained stable at 12-month follow-up. Although the OCD group reported reduced interpersonal problems post-treatment, the group still experienced more submissiveness compared to healthy controls. Interpersonal problems in OCD appeared to be more attributable to comorbid conditions than to OCD-specific symptoms. Although patients with OCD were found to have interpersonal styles that might cause some problems, these were minimal at baseline and did not significantly affect OCD treatment outcomes. Interpersonal problems in this population might be more strongly related to depressive symptoms than to OCD-specific symptoms. CBT was associated with slight improvements in interpersonal problems.