Generalised cortisol resistance is a rare disease due mainly to inactivating mutations of GR (glucocorticoid receptor) encoded by NR3C1 gene. We had the opportunity to explore one patient presenting with bilateral adrenal incidentalomas and abnormal cortisol secretion in whom we validated glucocorticoid resistance and NR3C1 mutation. We will describe in this short review the pitfalls of the diagnosis between Cushing's syndrome and hormonal resistance. We will recall the variable phenotypes of patients from real adrenal defiency to asymptomatic forms. Otherwise, we conducted a multicentric study MUTA-GR, of a cohort of patients presenting -y with bilateral adrenal incidentalomas and cortisol secretion abnormalities and/or arterial hypertension and we found (g that 5 % of the patients had NR3C1 inactivating mutations. The incidence of this kind of mutation seems more frequent than previously thought and the knowledge about its diagnosis E should be part of the skill of an experimented endocrinologist.