Depressive and anxiety symptomatology represent the most common psychiatric manifestations that complicate the management and prognosis of patients with somatic disorders. The Hospital Anxiety and Depression Scale (HADS) is a reliable, valid andpractical screening tool for identifying and quantifying anxiety and/or depression in non-psychiatric out patients. The aim of the present study was to compare the psychometric properties of the HADS among internal medicine outpatients, psychiatric outpatients and the generalpopulation. The present study involved 264 subjects: 95 internal medicine outpatients, 79 psychiatric outpatients and 90 normal controls. Psychiatric outpatients were diagnosed according to DSMIV-TR and inclusion criteria required the absence of any psychotic or organic psychiatric disorder. Patients with depressive disorders were divided in 3 groups: major depression, dysthymic disorderand adjustment disorder with mixed anxiety and depressed mood. All patients were administered the following psychometric tools: HADS, BDI and STAI. Subjects of the control group were administeredonly HADS. In all psychometric scales the psychiatric group presented significantly greater values than the internal medicine and the control group. In turn, the internal medicine group scoredsignificantly higher than the control group. Within the psychiatric outpatient group significantly higher HADS and HADS-D scores were observed in the major depression group followed by the dysthymicdisorder and the adjustment disorder with mixed anxiety and depressed mood group. HADS may be capable of identifying anxiety and depressive symptoms between psychiatric outpatients, internal medicine outpatients and subjects in the general population. In addition, the HADS-D subscaledifferentiates the main depressive disorders.