The artificial urinary sphincter is a totally implantable hydraulic prosthesis designed to restore continence without inducing dysuria. It is composed of 3 silicone elastomer elements: a periurethral or pericervical cuff, a pressure regulating reservoir balloon inserted in the retropubic space, and a pump situated in the scrotum or labia majora. The prosthesis is filled with a liquid containing a contrast agent. Pressure on the pump allows passage of liquid from the cuff towards the balloon and allows micturition. After 3 to 4 minutes, the liquid is automatically transferred from the balloon to the cuff to restore continence. The artificial sphincter is currently a very effective therapeutic solution in cases of severe urinary incontinence with 3 main indications: persistent incontinence after prostatic surgery, recurrent incontinence in women due to sphincter insufficiency, and certain forms of neurogenic incontinence. The Pitié-Salpêtrière Urology Department's experience currently consists of 200 implantations performed over the last 10 years. The overall success rate varies from 80 to 90% according to sex and the aetiology of incontinence, in patients in whom the sphincter remains in place. In fact, there is a risk of explantation due to erosion of the tissues by the cuff or infection, but this risk is less than 15%. The risk of prosthesis failure is about 20%, but after correction of the defective element, cure is achieved in almost every case. Analysis of the results in the first 120 patients with the two most frequent aetiologies and with at least three years' follow-up (range: 3 to 10 years) reveals: in a series of 75 men, treated for severe incontinence persisting more than one year after surgery for benign prostatic hyperplasia, the explantation rate was 15% and, in the patients in whom the sphincter remained in place, complete cure was obtained in 73% of cases without any incontinence, while 17% of patients suffered from minimal incontinence, not requiring protection, 7% had moderate incontinence requiring protection and 3% were considered to be failures. The revision rate for technical failure was 24%. In a series of 45 women with recurrent incontinence after surgery, due to sphincter insufficiency, the explanation rate was 13% and, in women in whom the sphincter remained in place, complete success was obtain in 78% of cases without any incontinence, while 17% suffered from minimal incontinence, usually not requiring protection, 5% require protection, with no failures and a revision rate for technical failure of 24%.(ABSTRACT TRUNCATED AT 400 WORDS)