A 13-month-old, neutered female domestic shorthaired cat was evaluated for vomiting, anorexia, and lethargy. The cat was icteric and hyperbilirubinemic. Radiographically a partially radiolucent proximal duodenal foreign body was suspected. Ultrasonographically, there was a foreign body at the level of the duodenal papilla and dilation of the common bile duct and cystic duct; a diagnosis of extrahepatic biliary tract obstruction secondary to a duodenal foreign body was made. Sonographic findings were confirmed at surgery and a duodenal foreign body was removed. This information defines duodenal foreign body as a cause of extrahepatic biliary obstruction in cats.