A series of 129 carriers of non-small cell bronchogenic carcinoma (BC), in whom computed tomography (CT) of the thorax was performed as part of the preoperative study, are presented. The results of CT were compared with those of thoracotomy in terms of sensitivity (SEN), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV). Thoracic wall (prevalence 0.18): SEN, SP, PPV and NPV were 0.65, 0.92, 0.63 and 0.92, respectively. In peripheral tumors these values were 0.85, 0.90, 0.69 and 0.96, respectively. CT demonstrating invasion of the thoracic wall thus requires confirmation for the purpose of surgical staging. If CT reveals an intact wall, however, surgery may take place immediately. Malignant mediastinal lymph nodes: (prevalence 0.36): SEN, SP, PPV, and NPV were 0.70, 0.89, 0.78 and 0.84, respectively. For peripheral tumors these values were 0.78, 0.93, 0.82 and 0.91, respectively. CT demonstrating malignant mediastinal lymph nodes should be confirmed by mediastinoscopy. If mediastinal malignancy is not observed by CT, thoracotomy may be performed in peripherally located tumors; in centrally located tumors, however, the absence of adenopathy should be confirmed by mediastinoscopy.