Partial cystectomy remains an uncommonly performed procedure in the urologist's armamentarium. Historically, it has had a limited role in the treatment of bladder cancer because of the variable reported success rate and because of the high success rate of local endoscopic excision. When patients with muscle-invasive lesions are appropriately selected, 5-year survival rates following partial cystectomy approximate those of radical cystectomy in the treatment of transitional-cell carcinoma while preserving a physiologically functioning bladder. Therefore, not only does partial cystectomy represent a valuable treatment option, but it appears to be the procedure of choice for local muscle-invasive transitional-cell carcinoma of the bladder when careful selection criteria are utilized. Future studies are needed to define its precise role in affording bladder preservation when used in association with adjuvant chemotherapy. Partial cystectomy also remains a surgical option for a variety of less common benign and malignant lesions of the bladder.