In the last decade, several neoadjuvant trials for NSCLC patients with mediastinal lymph node involvement (N2) have been scheduled. The uniform plan is based on clinical staging, therapy, clinical re-staging, surgery (when is possible) and, finally, pathological staging. The precise classification of tumor during the three different staging procedures is mandatory. Considering clinical re-staging and pathological staging, nowadays surgery could be considered correct for most of the patients enrolled in the neoadjuvant protocols including cases where a major clinical response has not been achieved. Several experiences demonstrated how often the clinical restaging overesteems neoplastic tissue by fibrosis and scar and could judge as unresectable patients with a minimal residual disease.