Annular pancreas is a condition for which the embryological development has been fairly definitively worked out. There are those, however, who feel that the anomaly does not necessarily represent a developmental error. Whether it is a result of failure of fusion of the ventral and dorsal anlage, however, or is due to simple hypertrophy is of little clinical significance (1). The importance of the annular pancreas lies in its recognition during life as a possible pathologic entity. By far the majority of cases have been found incidentally, at postmortem examination. There have been enough surgically corrected cases, on the other hand, to prove that the condition is often symptomatic. Why an annular pancreas of considerable extent, with marked narrowing of the caliber of the duodenum, in one individual produces no symptoms, and a less extensive lesion in another gives rise to many symptoms, is neither well understood nor explained. As a general rule, the deciding factor in the symptomatology is the severity of the duodenal constriction. The lesion is probably the only congenital anomaly of the gastrointestinal tract, which causes symptoms late in life (2). The majority of proved cases have been in patients beyond the age of forty or in the immediate neonatal period with signs or symptoms of high obstruction. We encountered only 2 cases in the literature proved during childhood and, for this reason, our first case is of interest: Case I: A 7-year-old male was admitted to the hospital on Oct. 14, 1958, because of intermittent abdominal pain and vomiting of several years duration. The episodes of pain might be several weeks or several months apart; they were cramp-like in character, causing the patient to double up. Invariably with the onset of pain, vomiting occurred. Each episode would last from one to several hours. The past history was non contributory except for the usual childhood diseases, without complications. Eating habits were not good and weight gain had been poor. Except for tenderness to deep palpation of the epigastrium, the physical examination was unrevealing. A diagnosis of mesenteric adenitis was made but, because of the duration of symptoms, a radiographic study was carried out. An upper gastrointestinal examination with barium showed a distinct narrowing of the entire descending limb of the duodenum; actually, this segment of bowel looked stretched. At its upper limit was a definite shelf, suggesting extrinsic constriction of the lumen on the right side of the loop. There was no gastric dilatation (Figs. 1 and 2). On the basis of the radiographic findings, a diagnosis of annular pancreas was made and an exploratory laparotomy was carried out. A segment of pancreatic tissue over 3 cm. in width was found encircling the duodenum at a point approximately 2.5 cm. from the pylorus. A posterior gastroenterostomy was performed.