The results of lung cancer treatment have not significantly improved for many years. About 35% of patients with non-small cell lung cancer (NSCLC) are in clinical stage IIIA. Clinically asymptomatic distant metastases occur in the majority of these patients. In such cases only combined treatment offers a chance of cure. In the Chest Surgery Center in Lublin a clinical trial was carried out aimed to assess late results of combined treatment in patients with IIIA NSCLC. Over 700 patients were enrolled in the study. The results of the trial disclosed, that neoadjuvant chemotherapy prolonged life of the operated patients and improved their life quality. However, a question of qualification for this complex treatment and complexity of assessment criteria, still remain to be answered.