The data presented in this paper demonstrate that a liver which has been severely damaged by protein malnutrition can be restored to normal composition, anatomy and functional capability by central venous feeding. An atypical serum protein electrophoretic pattern characterizes protein malnutrition. TPN repletion restores all of the protein fractions back to normal except for the gamma globulin levels. Liver nitrogen is a very sensitive index of both protein malnutrition and TPN repletion. The liver is dramatically effected by protein malnutrition and its return toward normal can be achieved by TPN support as demonstrated in this paper.