The urinary trypsin inhibitor (UTI) is responsible for most of the antitryptic activity in urine and is excreted in increased amounts in urine under certain pathological conditions such as cancer and bacterial infections. Our aim in this study was to better understand the mechanisms responsible for the increase in UTI excretion on surgical stress and thus to better appreciate the information provided by inflammatory mediators. Thirty-one consecutive patients who underwent radical esophagectomy for esophageal cancer were investigated in this study. We determined serum UTI and polymorphonuclear cell elastase (PMNE), urine UTI and evaluated the effectiveness of preoperative administration of methylprednisolone on the postoperative clinical course and adverse inflammatory reactions. The results revealed that urine UTI and serum PMNE levels in the steroid group were significantly lower than those in the non-steroid group. In addition, UTI levels correlated positively with serum levels of aminotransferases. More importantly, the maximum level of urine UTI in patients without complications was lower than that in patients with complications. These results suggest that urine UTI provides useful information concerning postoperative clinical course, and that preoperative administration of methylprednisolone may contribute to decrease postoperative complications following esophagectomy.