A B S T R A C TUretero-appendicular fistulas represents a rare entity, closely related to appendicitis and are usually encountered intraoperatively. A literature review showed six published cases -only one of them involving a pediatric patient. We describe the case of a ten year-old girl with history of recurrent urinary tract infections (UTIs) since the age of three. Following a six-year asymptomatic period, she was referred for evaluation after a new diagnosis of UTI complicated by a right distal ureteral stone. The patient underwent ureteroscopy and laser stone fragmentation. During the endoscopic procedure a mature, well-epithelialized ureteral tract to the peritoneal cavity was encountered. The procedure was converted to open exploration through a right Gibson incision, where an appendicular phlegmon associated with an uretero-appendicular fistula with passing of faecoliths to the ureteral lumen was found. An appendectomy was performed along with primary fistula closure. Uretero-appendicular fistulas represent a rare entity. Our case highlights the relation between this type of fistula with appendicitis, its unexpected intraoperative diagnosis and the unusual presentation, as the patient did not present clinical findings compatible with acute abdomen.