A national, evidence-based guideline on the staging and treatment of patients with non-small cell lung carcinoma (NSCLC) has been compiled by the various disciplines involved. The initial diagnostic measures in patients with suspected lung cancer include history taking, physical examination and chest x-ray. Additional examinations include CT scan of the chest and upper abdomen, bronchoscopy, and 18F-fluorodeoxyglucose-positron-emission-tomography(FDG-PET)-scintigraphy, if curative therapy is planned. Cervical mediastinoscopy or endoscopic echography with fine needle aspiration can be performed for mediastinal tissue staging. The preferred treatment in stage I, II or limited III is radical resection. Postoperative radiotherapy is recommended in cases of incomplete resection and can be considered in patients in whom mediastinal lymph-node metastases are unexpectedly encountered. Chemoradiotherapy is recommended in locally advanced NSCLC. In patients with NSCLC stage I-III and poor performance status, palliative radiotherapy may be the only feasible treatment. Some patients with NSCLC stage III and stage IV can be offered palliative chemotherapy and supportive care. In cases of doubt about operability, resectability, significant pulmonary or cardiac comorbidity or combined treatment, a specialist centre should be consulted. Diagnostics should be completed within 3-5 weeks. Ensuing surgery or radiotherapy should be carried out within 2 weeks. Follow-up of patients with NSCLC includes history taking, physical examination and an optional chest x-ray. In the first year after treatment patient visits are planned quarterly, in the second year half-yearly and then yearly for at least five years.