Masked depression is an endogenous or psychogenic depressive state in which the somatic symptoms predominate while the psychical symptoms are only present in the background. Therefore it is a matter of phenomenological diagnosis. An enquiry conducted among general practitioners in Germany, France, Austria and Switzerland has shown that up to 10% of the patients consulting a physician are suffering from depression and half of the cases are masked depressions. An enquiry disclosed in 1978 among 74 practising physicians proved that 18% of the patients seeking medical advice suffer from depressive states and that about half of the cases are masked depressions. Diagnosis and therapy of masked depression are of great practical importance in everyday practice because of its frequency. The diagnosis has to be established on the basis of the depressive background symptoms. The masked depressions often show anxious-hypochondrical character and therefore have to be treated with antidepressant drugs with anxiolytic effect. The choice of the antidepressant drug with the right activity profile is decisive for the success of the therapy. Finally, there is a short review about diagnosis and therapy of masked depression.