Replacement of the cervical trachea using Silasticprostheses was performed in sheeps with good long term results. 2. The superiority of subterminal suture cuffs is demonstrated. 3.A biological adhesive system supplementing the sutures of the anastomoses was highly effective. 4. The results of replacement of the canine tracheal carina are presented. 5. Since auto-, homo- and auto-alloplastic grafts do not epithelialize they are not capable of active secrection transport. Moreover they show a permanent tendency to shrink. We therefore conclude that the Silasticprosthesis is the best tracheal substitute available at this time for cases in which direct anastomosis is not feasible after segmental tracheal resection.