The aim of the present review is to describe the epidemiological and clinical aspects of autoimmune pancreatitis (AIP), and to report the data existing in the English literature on the usefulness of IgG4 serum levels, as well as of other serological markers in the diagnosis and follow-up of patients with AIP. The serum IgG4 subclass seems to be a good marker of AIP, and its determination should be included in the diagnostic work-up of this disease. The relationship between allergy and IgG4 serum concentrations in patients with AIP has also been reviewed. Finally, we have revised the current literature data on the imaging feature of AIP and the therapeutic modalities for curing AIP patients.