Congenital obstruction of the duodenum, first described by Calder (7) in 1733, was long considered a fatal malformation of the newborn and a subject merely of academic interest. In view of the rapid downhill course within a week or two after birth, the diagnosis was formerly made by the pathologist at the necropsy table. More recently, however, the condition has been recognized clinically and roentgenologically, and during the past decade surgical procedures have been carried out successfully (2, 5, 11,12, 13, 18, 19, 24, 25, 31, 38, 40, 43, 46, 48, 49). So far about three hundred cases have been recorded in the literature (32). Approximately fifty patients have been operated upon, one-half of whom survived. Due to improved methods, introduced by Ladd (29), Donovan (10), and their coworkers, the mortality rate has been still further reduced. In spite of these advances, however, the disorder has received but little attention in the roentgen literature (20, 26, 35, 44, 45). In this communication we shall re...