Familial glucocorticoid deficiency is a rare autosomal recessive disorder characterized by unresponsiveness to adrenocorticotropic hormone (ACTH), leading to deficient secretion of cortisol and adrenal C19 androgen precursors. Mineral-corticoid production, regulated by the renin-angiotensin system, is normal. The age of presentation varies from birth to 9 years of age, with approximately half of the patients presenting in the first year of life. In the neonatal period, patients usually present with hypoglycemia and jaundice. Hyperpigmentation and/or hypoglycemia are the main symptoms in older children. Tall stature has been described in several patients. The diagnosis of familial glucocorticoid deficiency is based on clinical findings, low serum cortisol in the presence of excessively elevated ACTH, the proof of normal aldosterone production, and the exclusion of other causes of adrenal failure.