Despite the variety of materials employable in the rehabilitation of the cervical trachea, long-term success is rarely achieved. Both gross and microscopic postoperative developments were studied on 45 dogs submitted to nine different types of reconstruction of anterior and circumferential defects. In the majority of cases, the grafts and prostheses used for repairs, enveloped by connective and inflammatory tissue, were either absorbed or expelled. Only pedicled autologous grafts survived rejection. Failure of tracheal replacements appears to be confined to tracheal and local phenomena. Such events impaired the incorporation of any type of graft or prosthesis.