A STUDY OF the use of a synthetic material in the repair of tympanic perforations of the middle ear was undertaken to determine if the use of such material would replace the use of autogenous tissue. The experiment was carried out on cats of adult age. The use of implants in various parts of the body is not new. 1-7 Reports of the use of various synthetic compounds including polyurethan, polysilicone, and polyvinyl as body implants are in the literature. Polivinyl was chosen as being the more pliable and more readily available in hospital sources of supply in the form desired. The cats used were adults weighing 9, 11, and 7 lb, respectively. The cats were anesthetized, the ears were cleaned, and an incision was made, using an electric cutting knife, from the sulcus between the tragus and antitragus8 inferiorly for 1 to 2 cm, thus exposing the region of