IgG subclass 4-related disease (IgG4-RD) is a rare but increasingly recognised fibroinflammatory condition known to affect multiple organs. IgG4-RD is characterised by unique histological features of lymphoplasmacytic infiltration, storiform fibrosis and obliterative phlebitis. In this review we describe the pancreaticobiliary manifestations of IgG4-RD, with particular emphasis on type 1 autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-SC). AIP and IgG4-SC can pose diagnostic challenges to the clinician as they may mimic pancreatic cancer and primary sclerosing cholangitis, respectively. We discuss current knowledge, clinical diagnostic criteria and recent advances and summarise the evidence base for current therapeutic approaches for AIP and IgG4-SC.