The lecture presents the current international guidelines on the diagnosis of hypopituitarism in children, in particular the rules of stimulation tests for the diagnosis of growth hormone deficiency, secondary hypogonadism and hypocorticism. It is recommended to use the anti-Müllerian hormone and inhibin B to diagnose different forms of hypogonadism. Genetic methods are also recommended to make a correct diagnosis, to prescribe a proper treatment and to provide a medical and genetic counseling of family members.