Intrinsic ureteral endometriosis is a very rare condition. A 41 y. o. woman with right hydroureteronephrosis and other aspecific symptoms came to our attention. The CT scan showed an ureteral obstacle causing the hydroureteronephrosis. She underwent ureterorenoscopy with biopsies of the lesion that did not result to be diriment. Suspecting a ureteral neoplasm, the patient then underwent ureteral resection and ureterocystoneostomy, and the extemporary histological examination resulted as endometriosis. The abdominal exploration showed a parametrial and a peritoneal growth - both compatible with the extemporary histological examination - that were also excised. The post-operative course was uneventful. The definitive hystological examination confirmed the perioperatory diagnosis. Intrinsic ureteral endometriosis is confirmed as a rare pathology with an indefinite clinical presentation; its typical presentation, namely cyclic hematuria, seems to be an anecdotal feature. Therefore the diagnostics of intrinsic ureteral endometriosis is still difficult even despite such a striking presentation.