The purpose of this study was to evaluate the clinical efficacy of 3D reconstruction of the tracheobronchial system using spiral CT. A total of 25 patients with tracheobronchial abnormalities, stenosis (n = 21) and fistula with esophagus (n = 4), underwent a single breathhold spiral CT (5 mm collision, 5 mm)/s increment). With respect to localization, extent and degree of stenosis and size of fistula were compared with findings at bronchoscopy. The CT location and extent of stenoses were consistent with bronchoscopic findings in all 21 patients. The diameter and shape of the lesions were not evaluated in five patients with severe stenoses. In patients with fistula, 3D CT image demonstrates the location and size of fistula in all four patients. Spiral CT serves to demonstrate accurate and useful 3D reconstruction images for planning and monitoring therapy.