Two hundred patients with histologically/cytologically confirmed clinical stage primary I-IIIA NSCLC will be included. The patients must be fit enough to undergo at least pulmonary lobectomy. Computer Tomography (CT) and Positron Emission Tomography (PET/CT) will be performed in all patients. Subsequently, the patients without evidence of dissemination will be randomized to transbronchial and transesophageal endoscopic ultrasound-guided needle aspiration ( EBUS-TBNA, EUS-NA) or Transcervical Extended Mediastinal Lymphadenectomy (TEMLA). The patients with N3 will be referred to definitive oncological treatment, the patients with N2 metastases will be referred to neoadjuvant treatment and the patients without N2/3 metastases will be operated on. The operative procedure will include at least lobectomy with complete lymphadenectomy, with open or video-assisted (VATS) technique. The patients undergoing sublobar resection will be excluded from this study. Final analysis will include comparison of the diagnostic yield and 5-year survival between the EBUS/EUS and the TEMLA arms.