A 39-year-old woman visited our hospital with a complaint of gross hematuria. Cystoscopy revealed a nodular tumor 3 cm in diameter in the posterior wall of the bladder. A transurethral resection was performed. This initial operation was complicated by unexpected intra-operative high blood pressure and visualization was obscured by bleeding. The histological diagnosis was paraganglioma. Therefore, a partial cystectomy was planned. Using cystoscopy, a 10 mm margin was identified and marked using electrocoagulation, followed by an open surgical procedure. After laparotomy, drainage veins were identified and ligated under the guidance of flexible cystoscopy lighting. Intra-operative blood pressure was stable during the operation, and the margin was negative for tumor.