Autoimmune processes are involved in the pathogenesis of diseases of several endocrine organs. There are also syndromes, where autoimmune diseases of multiple endocrine and other organs occur simultaneously. The pathogenesis of certain syndromes belonging to this group has been clarified recently and this made possible the discovery of previously unknown aspects of autoimmunity. In this review the authors present a brief synopsis of the pathogenesis and clinical features of autoimmune polyendocrine syndrome type 1 and the IPEX syndrome that are inherited as monogenic traits. Although the etiology of type 2 autoimmune polyendocrine syndrome and POEMS syndrome are not as well characterized as that of the aforementioned monogenic diseases, considering their clinical importance, the authors summarize the main features of these syndromes, as well.