The authors present 3 cases where the diagnosis of ectopic insertion of the ureter, responsible for incontinence, had been missed: -- 2 cases of refluxing urethral insertions, including 1 case of single ureter, -- 1 case of vaginal ectopic ureter with duplicity. The authors stress that an ectopic insertion of the ureter can be asymptomatic until adulthood when it may present as simply as urinary stress incontinence. The diagnosis is suggested by a history of incontinence developing since childhood, accompanied by radiological signs of pyeloureteric duplicity or a small atrophic kidney. When the diagnosis is missed, successive surgical treatments are bound to fail, while excision of the renal segment drained by the ectopic ureter results in cure.