A determination of the anatomic extent of tumor is important in planning appropriate invasive diagnostic procedures and treatment in patients with bronchogenic carcinoma. In most situations, plain radiographs provide useful anatomic information, but CT is necessary for detailed evaluation. Although some plain film and CT findings strongly suggest that a tumor is unresectable, they are usually nonspecific, and biopsy correlation is necessary before the patient is denied an attempt at a surgical cure. Also, in the light of recent advances in the surgical treatment of lung cancer, some lesions formerly thought to be unresectable because of local or regional metastases are being effectively treated. Close communication between the radiologist and surgeon is necessary in the appropriate management of these patients.