Endogenous hypercorticism in infants occurs extremely rare. The causes of Cushing’s syndrome in early childhood include space-occupying lesions and bilateral hyperplasia of the adrenal glands. ACTH-independent hypercorticism due to bilateral nodular hyperplasia of the adrenal glands in children in the first months of life is most often associated with McCune-Albright-Braitsev syndrome. This syndrome is a rare disease caused by hyperfunction of the stimulatory G-protein alpha-subunit due to somatic mutations in the GNAS gene. The McCune-Albright-Braitsev syndrome is a multicomponent disease, the clinical manifestations of which include café-au-lait spots, fibrous dysplasia, and different types of endocrine hyperfunction, among which hypercorticism is one of the rare cases. The clinical picture of Cushing’s syndrome manifested in early childhood is characterized by some peculiarities that can delay the correct diagnosis: the first manifestations include low weight and height at birth, physical retarfation in the absence of a redistribution of subcutaneous fat typical of Cushing’s syndrome, psychomotor retardation, and complications caused by immunodeficiency and hypertension. We present a case of ACTH-independent hypercorticism in an infant.