Autoimmune polyendocrine syndromes (APS) are organ-specific autoimmune disorders affecting multiple endocrine glands; these are gradually destroyed by action of autoantibodies. Similarly to other autoimmune diseases, the presence of certain genetic predisposition is an essential prerequisite to the disease development; polymorphism of the main histocompatible system (HLA in humans) appears to play the most important role. APS are categorized into four types, based on what combination of endocrine glands is affected. APS type 1, characterised by hypoparathyreosis, mucocutaneous candidiasis and Addison's disease, is frequently seen in childhood. For a more common APS type 2 to be diagnosed, Addison's disease together with autoimmune thyroiditis (Schmidt's syndrome) and/or together with diabetes mellitus type I (Carpenter's syndrome) must be present. The third type of autoimmune polyendocrine syndromes (APS type 3) involves the same disorder of endocrine glands as type 2 but usually without any defect of adrenal cortex. If the autoimmune endocrine gland disorder does not fulfil the criteria of APS 1-3, the disease may be categorized as autoimmune polyendocrine syndrome type 4. The authors present a case of 33 years old APS type 2 patient who, over 20 years, developed a wide range of autoimmune endocrinopathies, including endocrinopathies that are less common, such as adenohypophysitis, and are associated with other organ-specific diseases (coeliac disease). The case is presented to demonstrate the fact that APS represent a dynamic process and that it is always important to keep in mind that, over time, a patient may develop other autoimmune diseases. To conclude, the authors emphasise the recommendation to test patients with monoglandular endocrinopathy for the presence of any secondary endocrine disorders.