To clarify the prognostic factors for disease-free survival in completely resected pT2N0 non-small cell lung cancer, 81 consecutive patients who were treated between 1998 and 2001 were retrospectively reviewed. Follow-up was complete for all patients and the median follow-up time was 37.5 months. The overall 5-year survival rate was 68.6%, and the 5-year disease-free survival rate was 62.5%. Four factors (age, sex, visceral pleural invasion, and administration of tegafur and uracil) were proposed as prognostic factors for disease-free survival by univariate analysis. In multivariate analysis, visceral pleural invasion by the tumor (hazard ratio = 2.709, 95% confidence interval: 1.085 to 6.765, p = 0.033) and administration of tegafur and uracil (hazard ratio = 0.327, 95% confidence interval: 0.147 to 0.730, p = 0.006) were significant factors. Visceral pleural invasion was a prognostic factor for reduced disease-free survival in completely resected pT2N0 non-small cell lung cancer, and postoperative treatment with tegafur and uracil significantly improved disease-free survival.