AIMS Obsessive-compulsive disorder (OCD) is psychiatric disorder with a significant suicide risk, and the presence of alexithymia may increase this risk. As several studies attribute an important role, in OCD, to responsibility, the aims of this study were to evaluate possible clinical differences between patients positive or not for alexithymia concerning disorder severity, responsibility attitudes and suicide ideation and investigate which variables were associated with increased suicide ideation. METHODS 104 adult outpatients with OCD were recruited. Alexithymia was measured with Toronto Alexithymia Scale (TAS-20), attitude about responsibility was tested with Responsibility Attitude Scale (RAS), suicide ideation was assessed with Scale of Suicide Ideation (SSI) and depressive symptoms were evaluated with Montgomery Åsberg Depression Rating Scale (MADRS). Score of item #11 on the Y-BOCS was considered as a measure of insight. RESULTS Patients positive for alexithymia showed higher responsibility attitudes and more severe suicide ideation. In a blockwise regression model, the presence of lower insight, higher RAS scores and difficulty in identifying feelings dimension of TAS-20 were associated with higher SSI scores. CONCLUSIONS OCD patients with alexithymia may show higher disorder severity, lower insight and inflated responsibility, all related to suicide ideation, independently from depressive symptoms. Implications were discussed and study limitations considered and reported.