The human biliary tract offers an excellent model for gene transfer studies for a variety of diseases localized to the liver. The aim of this study was to determine if a viable liver might be employed to study viral transfection of the human biliary system in order to mimic in vivo human experiments. Using a normal human liver initially procured for transplantation, but subsequently found unsuitable, and with an intact biliary tree, the hepatic vascular supply was accessed for continuous perfusion. The common and left hepatic biliary system was isolated by balloon catheterization. A replication defective adenoviral vector containing the Escherichia coli β-galactosidase (lac Z) reporter gene (AdCMVLacZ) was injected into the catheter-isolated left and common bile duct lumen. Viral exposure to the right duct system was prevented by ligation. The bile duct segments were excised and prepared for enzymatic (X-gal) staining. Intense staining was observed in the biliary epithelium exposed to the adenoviral vector. No evidence of β-galactosidase staining was noted in the unexposed biliary mucosa. We report direct transfection of biliary epithelial cells from normal human liver with a recombinant adenovirus. Our data suggest potential therapeutic applications for therapy of hepatobiliary disorders.