traumatic lesions of the lung are common findings in patients with thoracic trauma. these lesions are increasingly diagnosed using computed tomography, mostly due to the fast acquisition time helical techniques that allow evaluation of critically ill patients and an efficient therapeutic management. the authors studied 150 patients with thoracic trauma submitted to computed tomography that demonstrated lung contusions, atelectasies, lacerations and hematomas. lung contusions were the most frequent lesions appearing as consolidation or ground-glass attenuation areas. atelectasies, in subsegmentar and compressive patterns, were the second most common lesions observed. lacerations appeared as consolidations with air or liquid level. lung hematomas, characterized by round opacities, were the most rare lung lesions seen in only five cases. in this study, blunt thoracic trauma accounted for the majority of 120 cases whereas penetrating trauma occurred in 30 cases. the causes of blunt trauma in decrescent order of frequency were motor vehicle accidents, pedestrian hit by car, falls, motorcycle accidents and trashing. penetrating traumas were caused by bullets or knives.