The aims of this study were to reveal the prognostic factors of cN2- pN2 and to define the criteria to select appropriate surgical candidates.From 1982 to 1997, 40 patients with cN2 were operated on, who actually had pN2. We retrospectively analyzed the survival of these 40 patients by means of a univariate and multivariate analysis. The overall 5-year survival rate of the cN2-pN2 patients was 21%. According to multivariate analysis, single metastatic MLN station, absence of parietal pleural involvement and low CEA level improved the prognosis. The 5-year survival rate of the patients with all of the three prognostic factors (n=6) was 67% and that of those with two prognostic factors (n=9) was 21%, compared with 0% in those with one or none (n=24) (p<0.01 and p=0.05, respectively). Even in cN2-pN2, patients with these three prognostic factors can benefit from primary surgical treatment, and can have long-term survival.