The aim of this study was to determine the clinical outcome of a bladder-sparing approach using chemoradiotherapy (CRT) for T1G3 bladder cancer. Between May 2000 and August 2007, 11 patients with T1G3 bladder cancer and who were negative for macroscopic residual tumor were treated by CRT after transurethral resection of bladder tumor (TUR-Bt). Pelvic irradiation was given at a dose of 40 Gy in 4 weeks. Intra-arterial administration of cisplatin and systemic administration of methotrexate were carried out in the first and third weeks of radiotherapy. One month after CRT, response was evaluated by restaging TUR-Bt. For persistent tumor after CRT or tumor recurrence, patients received additional treatment. Median follow-up was 21.2 months. Complete response was achieved in 10 of 11 patients (90.9%). Local recurrence for the entire group of 11 patients was 22.1% at both 2 and 5 years. Tumor progression was 0% at 5 years. Disease-specific survival rates were 100% at 5 years. All of survivors retained functioning bladders. Bladder preservation by CRT is a curative treatment option for T1G3 bladder cancer and a reasonable alternative to intravesical treatment or early cystectomy.