It is my purpose in this article to give in very concise form the essentials of diagnosis and treatment of urinary infections in infancy and childhood so that definite cure may be achieved in the simple forms of infection and relief obtained in the ones complicated by stasis or focal infection before irreparable injury of the kidneys occurs. In the acute stage the urinary infections usually manifest themselves with symptoms of fever and pyuria, while in the chronic stage they may be found accidentally. Stasis in the urinary passage that is sufficient to cause marked reduction of renal function may be present for years without infection; therefore a primary infection may be associated with permanent injury of the kidney. When the patient is an infant or a child, fever that occurs without demonstrable cause is a clue to urinary infection, and examination of the urine establishes the diagnosis. The presence