Postoperative infection of esophageal neoplasm surgery is the major cause of prolonged postoperative hospitalization, as well as morbidity. The clinical benefits of administering immune-enhancing nutrients (IEN) to critically ill patients and those undergoing elective surgery were clarified. However, the benefits of preoperative administration of IEN for patients with esophageal cancer remain unclear. The present study was designed to clarify the clinical efficacy of administration of IEN prior to esophageal surgery. A total of 123 patients undergoing esophagectomy in single institute were retrospectively investigated. All patients received postoperative enteral nutrition by use of ordinal nutrients. Preoperative IEN were also given to 84 patients (IEN group), while the other 39 received an ordinary diet (control). Postoperative courses and laboratory data were compared between the two groups. The incidences of infectious complications in the IEN and control groups were 18% and 38%, respectively (P < 0.05). Pneumonia developed in 5 (6%) IEN and 7 (18%) control patients (P < 0.05). Postoperative hospitalization was shorter in the IEN group (P < 0.01). Prealbumin levels, retinal binding protein levels and the lymphocyte count were significantly higher in the IEN group on postoperative day 3. These results suggest that preoperative administration of IEN in patients undergoing esophagectomy reduces infectious complications, mainly pneumonia, and shortens postoperative hospitalization.