This study reports the histologic changes seen in the biliary ductal system and pancreas as a result of endobiliary stenting. Ten mini pigs underwent endoscopic placement of suprapapillary endobiliary stents. The animals were killed and the liver, biliary tree, and pancreas were resected en bloc and prepared for histologic examination. Endobiliary stenting was found to result in significant chronic inflammation in the biliary system within 4 weeks of stent placement. These changes were present throughout the entire extrahepatic biliary ductal system and persisted throughout the 15-week study period. There was no significant acute inflammation in the biliary tree nor acute or chronic inflammation in the pancreatic duct. Further study is indicated to determine whether these changes will result in fibrosis and stricture.