In young rats (n = 117), with a liver weight of 9.9 +/- 1.6 g ("small livers"), the decrease of total liver blood flow was followed by necrosis of liver parenchymal cells in the first two postoperative weeks. These alterations induced by haemodynamic disorders occured since the hepatic artery-although dilated to its maximum--was insufficient to compensate completely for the decrease of the portal hepatic blood flow. In old rats (n = 33) with a liver weight of nearly the double (19.5 +/- 1.9 g; "big livers") the extrem haemodynamic situation after PCA with a more less sufficient arterial hepatic blood supply was followed by complete liver necrosis including necrosis of the v. Kupffer cells. Rats having survived the PCA-operation showed liver cell necrosis in a more less degree as opposed to the early changes. These changes were not thought to be due to persisting haemodynamic disorders but due to endotoxaemia as found in 85% of the animals by means of the Limulus Gelation Test.