Breast cancer (BC), the most common type of cancer in women of the Western world, is often associated with paraneoplastic syndromes (PNS). Autoimmune pancreatitis is a recently recognized entity belonging to the spectrum of IgG4-related systemic diseases, which are characterized by target-organ plasmacytic infiltration and fibrosis. In this report we review PNS associated with BC and we present the first case of BC-associated autoimmune pancreatitis as well as its successful management with steroids and immunosuppressive BC-tailored chemotherapy.