Seventy children with 71 renal injuries were observed from 1924 through 1961. Most of the children were over the age of ten and, in this group, four out of five injured were boys. In 15 children, the injured kidney was already diseased; this preexisting disease was the cause of death in four. Treatment was expectant in 46 and surgical in 25. Twenty-four of the children operated upon had a palpable mass and 17 had severe urinary bleeding. Surgery was necessary twice as often when the injured kidney was already diseased. Nine of the 46 children treated expectantly developed some disability secondary to the injury. Of the 13 children that had nephrectomy, a previously normal kidney was found ruptured in six and a hydronephrotic kidney found ruptured in five.