Abstract 1. 1. A case of duodenal obstruction and ulceration in association with annular pancreas in a twenty-eight year old man is reported. 2. 2. Preoperative roentgen study demonstrated marked duodenal dilatation and partial obstruction. A presumptive diagnosis of annular pancreas was made. 3. 3. No new etiologic factors were discovered for this anomaly. 4. 4. Successful relief of the duodenal obstruction was achieved by removal of the dilated duodenum, by subtotal gastric resection and by providing gastroduodenostomy distal to the pancreatic ring.