An experimental study of tracheal reconstruction using a separate piece of bronchus was performed in 6 dogs. After right upper lobectomy, a five-cartilage-ring length of the trachea extending from five cartilage rings above the carina was circumferentially resected; the right bronchus was transected just below the carina and above the second carina to provide the piece of bronchus, which was then interposed between the distal end of the upper trachea and the proximal end of the lower trachea by end-to-end anastomoses. One-stoma type carinal reconstruction (an anastomosis between the carina and the right intermediate bronchus) was performed. After completion of the airway reconstruction, the anastomotic site was wrapped with an omental flap. One dog died 14 days after operation due to anorexia and weakness, the necropsy in this dog revealed severe ischemic change of the interposed bronchus and ulcer formation at the stump of the upper bronchus. The other 5 dogs survived the operation. Bronchoscopically, the findings for the interposed free bronchus revealed severe ischemic change immediately after the operation, but almost normal findings were observed four to five weeks after the operation. The clinical relevance of this method of tracheal reconstruction is discussed.