Background and Objectives : The aim of the this study is to determine the efficacy of an external prosthesis made of ringed Polytetrafluoroethylene to prevent Postanastomotic stenosis after surgical correction of extensive tracheal defects in rabbits. Materials and Methods : Thirty rabbits were used, divided into two groups of 15 animals each. Group A rabbits underwent resection of six-ring segments of the cervical trachea and tracheal end-to-end anastomosis. The Procedure used in group B was similar to that used in group A. but the tracheal anastomosis was supported by an external ringed polytetrafluoroethylene prosthesis. After six months, rabbits were killed and tracheas were resected and then compared the postanastomotic tracheal stenosis using morphometry. Results : Anteroposterior diameter, transverse diameter, cross sectional area and intra luminal perimeter of trachea was greater in group B than group A. Also inflammatory changes of mucosa and submucosa were greater in group A than group B. Conclusion : A ringed PTFE as a external stent was effective to prevent tracheal stenosis resulting from the extensive tracheal resection and tracheal reconstruction in rabbits.