Autoimmune pancreatitis (AIP) is characterized by enlargement of the pancreas and irregular narrowing of the main pancreatic duct. AIP is often complicated by IgG4-related sclerosing cholangitis (IgG4-SC), in which the bile duct becomes narrowed. Endoscopic retrograde cholangio-pancreatography (ERCP) reveals irregular narrowing of the pancreatic duct and long stenosis of the bile duct as typical findings of AIP and IgG4-SC; however, it is difficult to differentiate localized AIP from pancreatic cancer and IgG4-SC from cholangiocarcinoma based on only ERCP images. The findings of intraductal ultrasonography are useful in differentiating IgG4-SC from bile duct cancer. Endoscopic ultrasound (EUS) can reveal hypoechoic enlargement of the pancreas and bile duct wall thickening. Elastography and contrast-enhanced EUS have the potential of improving the diagnosis of AIP. The ability of histological diagnosis of AIP using EUS-guided fine-needle aspiration (EUS-FNA) has improved due to improvements in technique and the new EUS-FNA needle. Steroid administration has been used to induce remission of AIP and maintenance of AIP treatment. Many problems regarding the indications of bile duct drainage and the use of im-munomodulating drugs remain to be solved.