Refinements of computed tomographic (CT) scanning techniques, such as high-resolution CT, CT densitometry, and contrast enhancement CT, have been shown to improve diagnostic accuracy in differentiating between benign and malignant lung nodules. Unfortunately, none of these techniques is fail proof, and, even when a lesion is considered to be benign, periodic observation is mandatory. In staging the locoregional extent of lung cancer, magnetic resonance imaging has not been shown to be superior to CT scanning and should not be substituted for or used in addition to CT except in special situations. Transesophageal ultrasonography, which identifies additional mediastinal lymph nodes that are not visualized by CT scanning, may become an important adjunct in the clinical staging of the regional extent of the disease. Study findings have supported the value of pleural lavage cytology at thoracotomy. Additional studies of the technique as a prognostic factor should be conducted in patients with resected early-stage disease. The high incidence of cerebral metastasis in patients with adenocarcinoma and stage III disease suggests the possible value of routine use of CT scans in this subset of patients who, otherwise, have potentially resectable lung tumors. However, no evidence supports routine scanning in patients with stage I or II disease. The low sensitivity of abdominal CT scans in identifying adrenal metastatic involvement further decreases the value of using this examination routinely to identify occult adrenal metastatic disease.