A group of 49 patients (41 males, 8 females) with locally confined non small cell lung carcinoma, of the average age 58.48 ± 9.05 years, was retrospectively analyzed. Bronchoscopy, computed tomography of the thorax and transesophageal echosonography were performed in all the patients to evaluate preoperatively the loco regional dissemination of the disease as well as the tumor resectability. The aim was to establish whether the complementary use of computed tomography and transesophageal echosonography could decrease the number of explorative thoracotomies. Resectability evaluation by computed tomography, burdened by many falsely negative results, could lead to 15 (30.61%) explorative thoracotomies. When transesophageal echosonography was performed, only 3 (6.12%) falsely negative results were obtained. Resectability evaluation by complementary use of computed tomography and transesophageal echosonography would be the best, with only 1 (2.04%) explorative thoracotomies necessary. By such procedure, it was possible to set the optimal indications for surgical treatment with the minimal number of explorative thoracotomies.