To examine the effect of preoperative total parenteral nutrition (TPN) on patients with Crohn's disease undergoing bowel resection, an historical cohort was assembled of 103 patients resected between 1982 and 1984 by a single surgical team. Preoperative, perioperative, and postoperative variables were compared between patients receiving TPN and patients not receiving TPN. Analysis was stratified for three surgical procedures: segmental small bowel resection, ileocectomy, and segmental or total colectomy The effect of TPN was most pronounced in patients having small bowel surgery. For segmental small bowel resection, 12 of 17 patients had TPN, and these patients had 20.4 +/- 14.3 cm less bowel resected than did those in the non-TPN group, an effect not dependent on duration of TPN. For ileocectomy patients, 31 of 62 patients received TPN, and these patients had 11.2 +/- 4.2 cm less small bowel resected than the non-TPN group, an effect not dependent on the duration of TPN. For large bowel resection patients, 6 of 24 patients had TPN, and there was no difference in length of bowel resection, preoperative and perioperative variables, or recurrence. The total hospital stay was 13.5 +/- 2.6 days longer for those having TPN; 3.5 +/- 1.9 days of the longer stay was postoperative. In conclusion, TPN was associated with reduced length of small bowel resection at the expense of longer hospital stay.