The data is presented on autoimmunological syndromes of polyglandular insufficiency (PGA). PGA I occurs mainly in children and includes chronic candidiasis of the skin and mucous membranes, adrenal and parathyroid failure. PGA II also called Schmidt syndrome occurs in adults and includes simultaneous development of Addison disease and thyroid failure, in half the cases insulin-dependent diabetes is present. PGA III is simultaneous development of thyroid failure and other immunological syndromes with exclusion of Addison disease. The isolation of PGA III has been questioned. Patients with PGA require substitutional treatment and monitoring for development of accompanying other autoimmune diseases.