The normal pancreas develops from three outgrowths of the primitive duodenum, two ventral and one dorsal. The ventral buds fuse early and then rotate with the gut, passing behind the duodenum from right to left and finally fusing with the dorsal outgrowth. The ventral component forms the inferior part of the head of the pancreas and uncinate process and its duct becomes the final channel of the main pancreatic duct. The remainder of gland and duct are derived from the dorsal outgrowth. To explain the development of annular pancreas, following theories have been put forward; 1 (i) persistence of left ventral anlage; (ii) adherence of the ventral anlage to the anterior duodenal wall preventing its rotation with the gut; (iii) fusion of the ventral and dorsal buds anteriorly before rotation has begun; (iv) ectopic pancreatic tissue developing in the region of the duodenum ‘per se' and later fusing with normal pancreas.Annular pancreas is one of the rare causes of duodenal obstruction in adults. The age of onset of symptoms depends upon the severity of constriction and associated stenosis or atresia of the duodenum if any15. Cases usually fall in two age groups - infantile (from birth to 4 years) and adults (from 17 onwards). When it occurs in infants, the mothers may have polyhydramnios. Other associated congenital anomalies are mongolism, oesophageal atresia with tracheo-oesophageal fistula, imperforate anus, duodenal atresia, malrotation of colon, cryptorchidism and Meckel's Divrticulum