Non-muscle-invasive bladder cancer is a frequent and heterogeneous disease with varying oncologic outcomes. The main goal in treating is to prevent recurrences and progression to muscle-invasive disease. Developments to improve the quality of transurethral resection of the bladder tumor and new chemotherapeutic options, including two device-assisted therapies, are being discussed. A problem is failure of intravesical therapy, especially failure after bacillus Calmette-Guérin treatment. Cystectomy is currently the treatment of choice for these patients. However, not all patients are willing to undergo cystectomy or are unsuitable for surgery. New therapies are needed for these patients. Therefore, the role of intravesical chemotherapy, immunotherapy and device-assisted therapy after bacillus Calmette-Guérin failure is also reviewed.