Six cases of avulsion of the upper ureter by blunt trauma are presented: 5 in children and one in an adult. One of these also involved the entire renal pedicle. A review of the literature shows that this type of trauma is rare, about 30 cases having been reported. They are seen mostly in children, and the right kidney is more prone to injury. Often, there is absence of hematuria which leads to considerable delay in diagnosis and surgical repair. On account of this delay, hydronephrosis, infection, and sometimes pseudocyst formation can complicate the initial pathologic condition. Despite these delays, successful repair can be accomplished and the kidney salvaged. In some instances, as we found out in our cases, a retrograde pyelogram was helpful in establishing the diagnosis and localizing the site of the lesion preoperatively. © 1979.