This review summarizes the current literature and tries to define the status of nuclear medicine in the clinical workup of lung cancer patients. Nuclear medicine procedures and positron emission tomography (PET) with the EMEA-approved radiopharmaceutical fluorodeo-xyglucose (FDG) are indicated for the characterization of lung lesions; the nodal staging of non-small cell lung cancer (NSCLC); the detection of distant metastases; and for the diagnosis of recurrent disease. Recent studies have shown the clinical efficacy of nuclear medicine and especially of FDG-PET in the workup of lung cancer patients and its significant impact on patients' management. Conventional nuclear medicine procedures are established for the pre-therapeutic assessment of pulmonary perfusion and function (lung perfusion and ventilation scintigraphy) and for the detection of bone metastases (skeletal scintigraphy). In studies in thousands of patients, FDG-PET has been proved to be the most accurate non-invasive diagnostic test for the characterization of lung nodules and masses. It can be recommended at least for patients with increased risk at surgery. FDG-PET should be applied in candidates for surgery of lung cancer, as mediastinoscopy may be omitted if PET shows no metastases in the mediastinum, and because FDG-PET avoids futile surgery by a more accurate selection of patients, especially by the detection of unexpected distant metastases. In candidates for thoracic radiotherapy, FDG-PET can help to exclude extrathoracic disease which needs systemic treatment and to better define the target volume for radiation therapy. The time has come for FDG-PET to find its place in new guidelines for the workup of lung cancer patients.