Total parenteral nutrition (TPN) rich in glucose may cause a deposition of triglycerides in the liver with consequent steatosis. We have valued the role of different nutrients in the determinism of liver failure. Sixty-five patients with severe and isolated head trauma (GCS score of 7 or less), 50 men and 15 women, of mean age 28 years (range: 15-68 years) were prospectively studied. All patients have a negative history for liver disease. In 24 randomly selected patients only glucose (group G) was administered as non-protein caloric source, while other 41 patients received glucose and Intralipid 10% (group GL) in ratio 70:30. The global incidence of cholestasis was 52.3% (34 patients): 17 patients (70.8%) of the group G and other 17 patients (41.5%) of the group GL (less than 0.025). No significant differences regarding the day of beginning of the cholestasis, the duration of TPN and the mean caloric and protein supply were pointed out. The liver steatosis was observed in 10 cases: 8/15 (53.3%) of the group G and 2/12 (16.7%) of the group GL (p 0.05). In conclusion, a TPN with glucose plus lipids is least toxic for the liver than only glucose.