VATS, video-assisted thoracic surgery, is presently used for a variety of thoracic disorders and represents a new approach to thoracic disease. It plays a specific role in staging, diagnosis and treatment of lung cancer. For precise mediastinal lymph node staging, cervical mediastinoscopy remains the gold standard. VATS can replace anterior mediastinoscopy and is useful to take biopsies of lymph nodes not accessible by cervical mediastinoscopy and to judge resectability of the primary tumour. Precise diagnosis of solitary pulmonary nodules is possible by VATS but protective measures should be taken to prevent spillage of tumour cells. Positron emission tomography has recently proven to be valuable in staging and diagnosis of lung cancer but its precise role remains to be determined. VATS is presently not advocated for definite treatment of lung cancer. The only possible exceptions are peripheral T1N0 squamous cell carcinomas smaller than 2 cm., but resections less than lobectomy are oncologically not adequate.