The authors observed a 24-year-old female with idiopathic fibrosing mediastinitis affecting the thoracic segment of the trachea and producing marked stenosis. Taking into consideration the common occurrence of cicatricial stenosis and the inefficacy of its conservative treatment, an attempt at one-stage allotransplantation of the trachea with omentopexy of the graft and the lines of anastomosis was made. In spite of immunosuppressive therapy (cyclosporine and azathioprine), signs of rejection appeared on the 10th postoperative day, which were arrested by antithymocyte globulin and loading doses of corticosteroids. Subsequently, the condition of the patient became stable. By the end of the 2nd month the graft appeared vital, its lumen being about 10 mm, the lines of anastomoses were epithelialized. Four months after operation signs of the graft stenosis appeared, possibly caused by progressive fibrosing mediastinitis. Because of this complication a silicon stent was used for the prophylaxis of further graft stenosis. This satisfactory result of tracheal allotransplantation is thought to be related to adequate selection of the donor-recipient pair, modern immunosuppressive therapy and utilization of omentopexy for early graft revascularization.