A preoperative nutritional assessment including anthropometry, biochemical indices and global subjective assessment was performed for 127 patients admitted for elective gastrointestinal surgery. Of these, 24 were subjected to minor surgery, 65 to intermediate surgery and 38 to major procedures. Patients were followed postoperatively, recording complications or mortality. Intermediate and major surgery patients had lower triceps skinfold thickness and mid-arm circumference and greater weight loss than did minor surgery patients. Thirty-six percent of the patients suffered complications. No association was found between preoperative nutritional status and incidence of postoperative complications. Six patients died and they showed greater preoperative weight loss (21 +/- 6.5 vs 12 +/- 1.4%) and lower serum albumin levels (25 +/- 4 vs 35 +/- 1 g/l) than patients who survived complications. Global subjective assessment classified 43% of survivors as malnourished, compared to 100% of patients who died.