In all patients with NSCLC, systematic nodal dissection was performed. Since 1981, 218 stage IIIA-N2 cases were resected. We registered 2 operative mortalities. Overall survival was 23% while, in completely resected cases, survival amounted to 30%. For long-term survival, favourable prognostic factors were cN2 T1-2 N2M0, single mediastinal node involvement and a tumor 20 mm or less in maximum size. The 5 yr survival rates of stage IIIA N2 patients was, respectively 48.1% with tumor diameter < 20 mm, 27.7% with diameter between 21-30 mm, 31.2% with diameter between 31-50 mm and, finally, 16.7% with tumors larger than 51 mm. When micrometastases to lymph nodes in p-stage I (stained with H-E) were examined with immunohistochemical staining, 27% (36 patients of 132) showed micrometastases.