Precise mediastinal lymph node staging in otherwise operable non-small cell lung cancer (NSCLC) is imperative as it determines subsequent treatment and prognosis. For mediastinal staging, even present-day computed tomography (CT) scanners have a low accuracy, and routine cervical mediastinoscopy is advised for precise lymph node assessment, certainly when considering a neoadjuvant protocol. Cervical mediastinoscopy remains the gold standard, and sampling of subcarinal nodes is essential. The role of remediastinoscopy after induction chemo- or radiotherapy remains to be determined. Extended mediastinoscopy is indicated to take biopsies of scalene lymph nodes or aorto-pulmonary nodes, which can also be reached by anterior mediastinoscopy. Video-assisted thoracic surgery (VATS) does not replace cervical mediastinoscopy but is a valid alternative to anterior or extended mediastinoscopy. A more complete exploration of the ipsilateral hemithorax is possible, with biopsies of aortopulmonary and inferior mediastinal nodes and judgment about resectability of the primary tumour.