For a variety of reasons, enteral feeding is frequently delayed following major abdominal surgery. The purpose of this study was to evaluate prospectively the feasibility and tolerance of early jejunal feeding following major upper gastrointestinal surgery. Beginning on postoperative day 1, patients (n = 167) received a full-strength enteral formula at the rate of 25 ml/hr through a jejunal feeding tube. Diets were advanced to the calculated target rate (25 kcal/kg/day) by postoperative day 4. Complications of tube feeding, calories received, and patient symptoms were recorded daily. There were no major complications or deaths resulting from placement of a jejunal tube or from early enteral feeding. Patients had abdominal symptoms such as cramping, distention, nausea, and diarrhea on 9%, 18%, 4%, and 24% of all feeding days, respectively. The majority of these symptoms, with the exception of diarrhea, were graded as mild. Patients undergoing surgery for pancreatic malignancy had significantly more diarrhea than patients undergoing esophagectomy or gastrectomy. Despite these differences in symptoms, patients received an average of 78% of their targeted caloric goal by postoperative day 4 and maintained this level throughout the study. Early enteral feeding for patients undergoing esophageal, gastric, or pancreatic resections is both safe and feasible despite the occurrence of predominantly mild gastrointestinal symptoms.