Over a ten year period of time from 1.3. 1962 to 31.12. 1972 at the Dept. of Surgery, University of Heidelberg 104927 patients were admitted to the hospital, 77950 operative procedures were carried out and 4217 patients died post operatively. The etiology of death as related to age distribution, disease and time of postop. death are discussed. The lethality causes are demonstrated by the classification of Petren. Autopsy examination reveals cardiac and/or circulatory failure to be the main cause of death (26,4%), followed by malignant tumors (12,7%), pneumonia (12,6%), cerebral causes (10,2%) and peritonitis (9,5%). Possible consequences of the distribution are being discussed.