Obstruction of the distal duodenum may result from congenital diaphragm, annular pancreas, pancreatic tumors, mesenteric vessel pressure, occluding veils and adhesions, megaduodenum, and other1-9 causes. Essentially, the obstruction is due to mechanical factors causing extrinsic occlusive pressure or to intrinsic occlusions, the result of ulcers, diaphragms, or other processes. This essay concerns the management of obstruction due to duodenal diaphragm in the adult. It will be shown that in the adult chronic incomplete obstruction causes a proximal duodenal dilation and hypertrophy. Pylorospasm is at first associated to enable the duodenum to empty distally. After some time the pylorus may become permanently patulous, and distal emptying may then no longer be possible. In infants, one of the most frequent causes of distal duodenal obstruction is congenital duodenal diaphragm. Duodenojejunostomy, first done by Stavely,10 has been the treatment of choice. Gross11 reports generally good results in a series of