We report our experience on 24 UPJ obstruction, that underwent endopyelotomy. The follow-up on these patients range from 12 to 72 months. The success rate, based on patient symptomatology as well as urographical and scintigraphical parameters, was 83.3%. An adequate selection of cases, with grade of hydronephrosis and crossing vessels pre-operatorial detection, would possibly show a further improvement of success rate. The antegrade transpelvic endopyelotomy adopted in the most recent cases, allows the identification of crossing vessels and the performance of a safer endopyelotomy. The average operating time was very short, while morbidity was limited to 3 cases (2 of gross haematuria and 1 urosepsis). All this shows that endopyelotomy is the first choice treatment of UPJ obstruction.