New insights into bladder cancer mechanisms have not yet produced clinical benefit. Without novel treatments, cystectomy remains the most effective local treatment, albeit the most aggressive. Uncertainty about the natural history of bladder cancer, the progression rate after other treatments, the risks of cystectomy and subsequent quality of life, foster debate about the indications for cystectomy. There are numerous urinary diversions and bladder substitutes. Differences in tumour extent, patient age, performance status, renal and mental function, and acceptance make different diversion techniques necessary. Urologists need not know every technique, but should know at least one technique of each class: an incontinent diversion (such as the ileal conduit), ureterosigmoidostomy, continent reservoir, and orthotopic bladder substitute. The common principles, advantages, and contraindications of these techniques are discussed.Semin. Surg. Oncol. 13:350‐358, 1997. © 1997 Wiley‐Liss, Inc.