Rare adrenal disorders comprise those with hormonal oversecretition and/or overgrowth and those with inappropriate low endocrine functionality. While oversecretion and tumour growth often requires surgical or targeted medical therapy, patients with adrenal insufficiency are in need of specialized care for hormonal replacement therapy. In all cases, specialized endocrine diagnostic approaches with baseline and dynamic tests are necessary. In many instances these are substituted by dedicated functional imaging procedures, invasive hormonal analyses and/or targeted genetic testing and counselling. In cases of malignant adrenal tumors specialized multidisciplinary teams are required for personalized therapy decisions.