Autologous fibrin tissue adhesive is currently the most promising adhesive for otologic use with respect to strength and biocompatibility without the risk of transmissable disease that is of concern with the commercially prepared fibrin adhesive. We set out to evaluate the practicality of preparing autologous fibrin adhesive in cats and to see if the adhesive's duration and strength of bonding was sufficient to allow natural tissue union to occur with various grafting materials. Autologous fibrin adhesive was prepared preoperatively from ten cats using the ammonium sulfate precipitation technique. Twenty otologic procedures were performed in which the incus long process was resected and the defect bridged with one of four grafting materials: autograft ossicular bone, bone pate-fibrin glue, porous hydroxylapatite, and Plastipore-bone pate. All grafts were secured with the autologous adhesive. The cats were sacrificed at 6 and 12 weeks. We found the the autologous adhesive provided adequate duration and strength of support to enable a firm tissue union between all the grafting materials and the adjoining incus and stapes.