Focused high-energy shock waves (6,000 to 10,000 shots) were targeted under ultrasound guidance onto implanted urinary bladder cancer in rabbits to elucidate its effect. Although only focal necrosis of the tumor was seen following 6,000 to 10,000 shots daily for 3 days or following chemotherapy (THP-adriamycin) alone, almost total tumor necrosis was observed following a combined shock-wave therapy for one day and THP-adriamycin administration, demonstrating an additive and/or synergetic effect on rabbit urinary bladder cancer.