The German version of the Beck Depression Inventory (BDI) was administered to 477 depressed in- and out-patients, 180 patients with chronic pain and 86 matched healthy control subjects. Earlier studies have applied the German BDI successfully, but only on students and other non-clinical samples. The clinical use of the BDI was found to have good internal consistency and validity. Cronbach's alpha reached 0.88, the average item-total correlation was 0.47. With one exception (weight loss), all items showed significant item-total correlation with the overall severity of depression. Correlations with other self-rating scales were 0.72 and 0.74 and with the Hamilton rating scale 0.34 and 0.37. A factor analysis showed a general factor as the most appropriate solution. Age, sex, and diagnostic subgroups (e.g. endogenous depression) had no significant influence on these results. A score of 18 and higher indicates depressive symptoms severe enough to require further clinical consideration. The BDI is also sensitive to changes in symptomatology over one week or one month, and can be used for pre-post comparisons in psychological and/or pharmacological interventions. Altogether, the German BDI proved to be a useful psychometric instrument for measuring the intensity of depressive symptoms in clinical samples.