Patients with cancer of the upper digestive tract may present with malnutrition, which may cause immunodepression and an increased rate of postoperative complications. In this study we describe the rationale and the feasibility of immediate postoperative enteral nutrition (NEPI) and evaluate its effectiveness for the nutritional support of patients undergoing surgery of the upper digestive tract. We studied 46 patients undergoing the following procedures: total gastrectomy (n = 22); oesophageal resection (n = 12); duodenocephalopancreasectomy (n = 12). NEPI was started on postoperative day 0 with a polymeric diet (calories: 53% as CHO, 22% as proteins, 25% as lipids) aiming at a calorie intake of 25 Kcal/Kg/day by postoperative day 4. It was possible to administer 24 Kcal/kg/day with the enteral diet from the 4th to the 10th postoperative day. Oral intake was resumed on average on postoperative day 13, and the mean hospital stay was 27 +/- 17 days. Tolerance of NEPI was good in most patients: only 5 patients (11%) interrupted the enteral nutrition. The mean postoperative weight loss was 3.7%. The rate of septic complications was 27%; mortality was nil. The surgical procedures caused a transient and reversible acute-phase decrease of nutritional and immunological parameters in the early postoperative period. However the NEPI preserved the nutritional status postoperatively as shown by the lack of significant changes in the nutritional indices at 10-14 days after surgery, as compared with baseline. In summary, we documented that NEPI can be started from postoperative day 0 with good intestinal tolerance, allowing adequate nutritional support, after extensive surgical procedures on the upper digestive tract.