The gross and microscopic anatomy of the biliary tract of the ferret was studied. The liver consisted of six separate lobes. The coronary ligament was not present. Histologically, it was very similar to that of man. The gall-bladder was present and was a pear-shaped sac. Its muscle coat was very thick and well developed. Hepatic ducts were multiple. Minor hepatic ducts formed three major ducts, the left, central and the right. A single common hepatic duct was not present. The cystic duct generally arose from the central duct. The bile duct was formed by the union of three major hepatic ducts. The pancreas consisted of two limbs, the left and the right. Each limb was drained by a duct which joined and formed a short main pancreatic duct. An accessory pancreatic duct extending from the duct of the left limb of the pancreas was usually present. The main pancreatic duct joined the bile duct nearly at right angles prior to the entry into the duodenum. Both ducts entered through the same osteum and coursed together. They ended in a common ampulla which opened into the major duodenal papilla situated at about 2.75 cm from the pylorus. The sphincter of Oddi was present and was very similar in disposition to that of man. The sphincter choledochus (of Boyden) was well developed. An accessory pancreatic duct was usually present. It opened into the duodenum at a minor papilla which was not prominent. The minor papilla was situated proximal and medial to the major papilla. Mast cells were not seen in the connective tissue sheaths of the liver, gall-bladder and pancreas.