Hypocaloric peripheral parenteral nutrition during the postoperative period aims to reduce or minimize protein loss and avoid use of central venous catheters. The efficacy of such nutrition in regard to postoperative outcome and nitrogen balance was evaluated in comparison with standard fluid therapy. The study was performed on 49 well-nourished patients who underwent major surgery for non-neoplastic conditions. Group I received 1 g amino acids + 1 g xylitol and 1 g sorbitol/kg body weight, while standard fluid therapy was given in group II. No significant intergroup difference was found in serum levels of albumin, total protein, prealbumin, transferrin or retinol-binding protein. The blood urea, nitrogen excretion and nitrogen balance were significantly higher in group I. The postoperative outcome was similar in both groups, as were the observed complications. Thus although the nitrogen balance was superior in group I, no intergroup difference was clinically evident.