The best surgical technique in bronchial reconstruction is resection and end to end anastomosis, but in some cases either pathology length, reduction in tissue elasticity, or such circumstances, patch bronchoplasty may be necessary to reestablish air-passage continuity. The purpose of this experiment would thus try to investigate the possibility of using ringed polytetrafluoroethylene (PTFE) graft to repair the diseased bronchus. A 2 x 1 cm patch segment of bronchus resected in 10 dogs were followed up with monthly bronchoscopy and endoscopic photography. Euthanasia was performed at 3, 6 and 9 months or when signs of respiratory distress developed. At postmortem examination, the anastomoses were examined grossly and with light microscopy. In 5 of the 10 dogs that underwent bronchial repair with PTFE, granulation tissue developed at the anastomoses resulting in airway obstruction after 6 to 9 months. No epithelial growth occurred over the graft between the suture lines. We conclude that the granulation tissue formation at the anastomosis and the lack of respiratory epithelial ingrowth across the graft makes PTFE unsuitable for patch repair of the bronchial defect.