A 52-year-old woman had concomitant cervical intraepithelial neoplasia (CIN) grade 3 and vaginal intraepithelial neoplasia grade 3. On performing a loop electrosurgical excision procedure, a vesicovaginal fistula accidentally occurred. The vaginal intraepithelial neoplasia covering the anterior fornix could have been a contributing factor in the occurrence of the fistula.