The Beck Depression Inventory (BDI) is one of the most widely used self-report measures of depression in both research and clinical practice. The Beck Depression Inventory Second Edition (BDI-II) is the most recent version of the BDI. The objective of the present study was to assess the psychometric foundations of the Icelandic translation of the BDI-II, adding to its international knowledge base. Participants were in total 1454, 1206 students and 248 outpatient-clinic patients. All students completed the BDI-II and a subgroup (n=142) completed additional measures of anxiety and depression. The Mini-International Psychiatric Interview (MINI) and the BDI-II were administrated to the patients. Convergent and divergent validity of the BDI-II were supported. It discriminated satisfactorily between patients diagnosed and those not diagnosed with major depression. Confirmatory factor analyses revealed small differences between various factor models of the BDI-II, derived from previous studies. However, a model of three first-order factors (cognitive–affective–somatic) and one second-order factor (general depression) offered an acceptable description of the item covariance structure for the BDI-II in both samples. It is concluded that the psychometric properties of the Icelandic version of the BDI-II are supported in patient and student populations.