It is the purpose of this study to point out the epidemiological importance of pathoanatomical records. In this connections, it is necessary to pay attention to different prerequisites for documentation, especially to an agreement on diagnostical nomenclature. Liver alterations and liver diseases are given as an example for valueing the relevance of both bioptic and autoptic materials for epidemiological purposes. By means of about 8,500 liver biopsies and 1,000 autopsies from the same territorial region the type and frequency of the different pathological alterations of the liver are compiled. Their frequency differs about ten fold. The epidemiological value obviously lies in specially aimed investigations; on the other hand, autoptic examinations are more representative and therefore of higher general reliability and greater epidemiological value.