The authors after studying eight different cases of ectopic ureters, try to illustrate the most important points of the diagnostic course in this pathology. In fact, in this field of studies, it is not easy, every time, to define diagnosis by the usual ways of investigation, so the authors describe just those cases which were missed by past clinical evaluations. They want to demonstrate by their experience of work, that it is possible to avoid a wrong diagnosis by an accurate evaluation of the clinical phenomenology, but most of all by a good research and right interpretation of the clinical and radiologic signs, direct and not, of this pathology.