We report an extremely rare case of IgG4-related sclerosing cholangitis with pancreas divisum. A 62-year-old man presented to our hospital with obstructive jaundice and hilar bile duct stenosis. An inflammatory tumor was suspected due to elevated of blood IgG4 levels. Endoscopic retrograde cholangiopancreatography revealed hilar bile duct stenosis and pancreas divisum. The biopsy specimens obtained by endoscopic ultrasonography-guided fine-needle aspiration biopsy (EUS-FNAB) revealed inflammatory findings. Steroid hormone therapy at an initial dose of 30mg/day resulted in dramatic improvement of the bile duct stenosis and blood chemistry data.