In an analysis of 75 children with stenosis of the ureter opening, our results are compared to those in the literature (see in particular Tables 1 and 2). Abdominal pain stands out as the major symptom in more than half of the children. In our cases, intramural disturbances predominate in ca, 2/3 of cases, in the literature in about half of cases. The occurrence of extramural disturbances (accessory vessels, adhesions, higher opening of the ureter) occurs with equal frequency. The determining diagnostic procedure for stenosis of the ureter opening is an excretion urogram. Indications for a retrograde pyelogram and the performance of a micturation cystoureterogram are discussed. The operation of choice for stenosis of the ureter opening is the plastic operation of the renal pelvis of Anderson-Hynes, which has a success rate of at least 80%. Amoung our group of patients, primary nephrectomies were only seldom necessary.