Autoimmune polyglandular syndromes are classified into three types. Type I occurs in childhood and is characterized by at least two of the following: chronic mucocutaneous candidosis, adrenal failure and hypoparathyroidism. There is also an association with chronic active hepatitis. Type II usually develops in adulthood and is characterized by adrenal failure plus hypothyroidism or diabetes mellitus, or both. Type III consists of thyroid disease and one other organ-specific autoimmune disorder. This classification has potential usefulness in patient management and family screening for autoimmune endocrine diseases.