The basic concepts of autoimmune pancreatitis as a disease with complicated pathogenesis including not only autoimmune factors proper but also infectious and hereditary ones are considered. Difficulties encountered in diagnostics of pancreatitis arising from the absence of characteristic clinical, laboratory, and instrumental signs of this pathology are discussed. The main morphological features of two types of autoimmune pancreatitis are described as being of diagnostic value, viz. Meyo Clinic criteria (HiSORT), that allow in the majority of the cases to correctly differentiate between autoimmune pancreatitis and pancreatic tumours. The main approaches to the treatment of autoimmune pancreatitis are presented including the application of steroids at the early stages of the disease and enzyme replacement therapy at the later stages.