To evaluate the effects of hepatic vagal denervation on the adaptation of glucose metabolism to short-term starvation (i.e., < 24 h), glucose metabolism was studied after 16 and again after 22 h of fasting in postsurgical patients with truncal vagotomy (n = 9; radical resection of esophageal carcinoma) and without truncal vagotomy (n = 5; partial resection of the large bowel for carcinoma). Glucose metabolism was studied 3-7.5 mo postoperatively by [3-3H]glucose turnover and by indirect calorimetry. Basal glucose production, plasma glucose concentration, glucose oxidation, serum free fatty acid concentration, and fat oxidation were not different between groups; neither were plasma concentrations of glucoregulatory hormones. The adaptation to prolongation of the fast by 6 h was not different for any of these parameters between both groups. In conclusion, truncal vagotomy does not affect the adaptation of glucose metabolism to the postabsorptive state (16-22 h of fasting).