Liver biopsy specimens were taken in 350 patiens during laparotomy and examined histologically. In 27.7% of all cases liver cell necrosis with invasion of granulocytes could be demonstrated, however only when biopsies were taken at least 45-60 min after start of surgery. There is no clear evidence, that the occurrence of this type of necrosis depends on the method of narcosis, the age of the patient, the severity or duration of the underlying disease, on the presence of cholangitis, cholestasis or fatty infiltration of the liver. Cell necrosis occuring during surgery arises primarily in the centrolobular areas as single cell necrosis; in rare cases however confluent and extended necrotic changes may occur. Etiology, pathogenesis and significance of the lesions are discussed. The frequency of other changes of the liver diagnosed inadvertently during these investigations is discussed as well.