Objective: A prospective randomized trial was performed to investigate the prognostic advantage of postoperative adjuvant chemotherapy in patients with resected stage I-II non-small cell lung cancer (NSCLC). Patients and methods: From March 1992 to December 1994, 221 patients with completely resected stage I-II primary NSCLC were enrolled and randomly assigned to two groups, as follows: 2-year oral administration of Uracil plus Tegafur (UFT) (adjuvant group, 109 patients), and surgical treatment alone (control group, 110 patients). Results: The overall 5-year survival rates were 79% for the adjuvant group and 75% for the control group, and there was no statistical significance. The 5-year disease-free survival rates were 78% for the adjuvant group and 71% for the control group, and there was also no statistical significance. There have been seen no severe complications in the adjuvant group. The mean total dosages of UFT were about 75% of maximum basic amount. Conclusions: The UFT regimen was feasible. However, we have not observed any survival benefit in the adjuvant group. Larger trials are needed to confirm the effect of UFT to patients with resected NSCLC. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.