A comparative nutritional study in brain-injured patients (BIP) was performed to assess the influence of a combined enteral-parenteral nutrition (CN) and a total parenteral nutrition (TPN) on protein catabolism in the early posttraumatic period. 20 male BIP (Glasgow coma scale 5-7) were randomized to one of the two feeding regimes. Nutritional support was based on 150-175% basic energy expenditure. Amino acid intake was 1.4 g/kg/day in the TPN and 2.4 g/kg/day in the CN group. Negative nitrogen balance (NNB) averaged means = 11.3 g/m2/day (SEM = 3.06 g/m2/day) in the TPN group and means = 10.2 g/m2/day (SEM = 2.33 g/m2/day) in the CN group. Between both feeding regimes not statistically significant differences could be observed concerning mortality, N-balance, creatinine and 3-methylhistidine excretions. Protein concentration of the regurgitated gastric fluid was significantly higher in the CN than in the TPN study group. Data imply that both alimentary regimes are of similar value, but BIP with impaired gastric function, such as high tube reflux, are better treated by TPN.