Ectopic ureter is quite a rare malformation, and it can be more or less serious depending on its anatomy (monolateral or bilateral ectopy, duplicated ureter, single ureter) and the associated malformations. It's more common in female patients. Ectopic ureteral orifice can be either intravesical (bladder neck) or, more often, extravesical. Ectopia in women is more frequently found in the urethra and the vaginal vestibule; much less frequently in vagina and in uterus. In men it is mostly found in the posterior urethra; in the male genital tract is very rare. In most cases ectopic ureter is associated with pyelo-ureteral complete duplication: the upper kidney usually works badly or doesn't work at all, due to renal dysplasia or pyelonephritis. More rarely ureteral ectopia affects a single urinary system and can be monolateral or, in the most serious forms, bilateral. The main clinical signs are urinary incontinence accompanied by regular micturition (more exactly pseudoincontinence) in the female patients, and urinary infection. In the male there is no urinary incontinence. Authors report their experience about 54 ectopic ureters in 51 children. Treatment is always by surgery: the choice has to be made between conservative or radical attitude. 38 total exeresis of the ectopic excretory pathway (upper heminephroureterectomy or nephroureterectomy), 9 ureteral reimplantations, 1 uretero-pyeloanastomosis have been done. Outcome is always satisfactory in monolateral forms, more uncertain in bilateral forms with single ectopic ureter, due to incontinence and reduced bladder capacity problems and the possible associated renal failure.