Purpose: To evaluate the efficacy of postoperative adjuvant chemotherapy for completely resected p-stage I non-small cell lung cancer (NSCLC). Materials and methods: Patients who underwent complete resection with lymph node dissection for p-stage I NSCLC (T1N0,T2N0, adenocarcinoma or squamous cell carcinoma, were eligible. After surgery, 150 patients were stratified according to tumor size and histologic type, and then randomly assigned to 1 of 3 groups (50 patients each group): surgery alone (control group), surgery with chemotherapy; PVU group (2 courses of cisptatin 80 Mg/m(2), i.v. x 1 (day1), vindesine 3 Mg/m(2), i.v. x 1 (days 1 and 8) and UFT 400 mg/day, p.o. for a period of 2 years), and LIFT group (UFT 400 mg/day, p.o. for 2 years). Results: The 5-year survival rates of the PVU group, the UFT group, and the control group were 87.9, 67.7, and 66.3%, respectively. The difference in 5-year survival between the PVU group and the control group was statistically significant (p = 0. 045, log rank). The 5-year disease-free survival rate of the PVU group (81.1%) was also significantly better than that of the control group (66.5%) (p = 0.042, tog rank). According to multivariate analysis using Cox's proportional hazard model, the only significantly positive factor on outcome was PVU chemotherapy after surgery. Conclusion: Postoperative PVU chemotherapy is effective for Japanese patients with completely resected p-stage I NSCLC. (c) 2005 Elsevier Ireland Ltd. All rights reserved.