ABSTRACTGlucocorticoid hypersensitivity syndrome has been reported to date only in several patients. This article describes a unique case of this syndrome in a 24-year old female admitted to hospital because of arterial hypertension and obesity. Although her clinical picture suggested Cushing’s syndrome, she had low adrenocorticotropic hormone (ACTH) and cortisol levels with a poor response to corticotrophin-releasing hormone and Synacthen. In turn, an overnight dexamethasone suppression test with 0.25 mg of dexamethasone led to a dramatic decrease in morning cortisol. A diagnosis of glucocorticoid hypersensitivity was made and the patient started treatment with ketoconazole and cabergoline, which resulted in some clinical improvement. This case illustrates the need for clinical awareness of glucocorticoid hypersensitivity in patients suspected of Cushing’s syndrome.