We used the Tuscan Cancer Registry archives to retrieve records of 2,896 patients with a histological diagnosis of lung tumor from January 1996 to December 2000. Of 2,410 patients with non-small-cell lung cancer, 767 (31.8%) underwent complete resection. The following variables were analyzed for their influence on survival in the 157 patients with pathologic N1 status: sex, age, cell type, pathologic tumor status, number and level of involved lymph nodes, tumor grade, and type of surgery. Overall 5-year survival rates were 43.9% for 417 patients with pN0 disease, 10.8% for 176 with pN2 disease, and 31.6% for those with pN1 disease. In pN1 disease, the overall 5-year survival rates for patients with hilar and non-hilar lymph node involvement were 27.4% and 39.6%, respectively. Univariate analysis demonstrated that pathological T status and level of N1 involvement were significant prognostic factors. Cox proportional hazards analysis indicated that hilar lymph node involvement was an independent prognostic factor. N1 lymph node status was identified as an independent prognostic factor in a combination of subgroups with different prognoses.