In an effort to determine whether transitional tumor cells will preferentially implant on the cauterized urothelial surface, a reproducible technique for cauterization of a portion of the murine bladder was established. This technique simulated a transurethral fulguration of a bladder tumor in humans. Transplantable tumor cells (1 X 10(6)) were placed transurethrally into the bladder of 50 mice. Twenty-five of these mice each had a portion of their bladder cauterized prior to insertion of tumor cells. Implantation with subsequent tumors occurred in 54% of mice with cauterization, in contrast to 12% of mice with an intact urothelial surface (P less than 0.005). Intravesical thio-tepa, mitomycin C, and cis-platinum were capable of significantly reducing the incidence of implantation. These results suggest that seeding may be a contributing factor to the high recurrence rate following endoscopic resection or fulguration of bladder tumors and that intravesical chemotherapy initiated shortly after surgery may reduce the incidence of implantation.