Disorders of control mechanisms caused by glucocorticoid hormones of adrenal cortex have a significant role in the pathogenesis of infectious diseases, first of all, due to cortisol, one of the key hormones with anti-inflammatory activity. Currently the conception about the mechanisms of cortisol influence, its functional abilities, connection with immune and nerve cells, involvement in cytokine regulation, features of free-radical oxidation has been extended. There has been identified the dependence of cortisol influence upon the isoform, amount and affinity of its receptors on target cells. The present review describes the study results concerning cortisol level in case of the most often occurring infectious diseases in children acute respiratory and intestinal infections, infectious diseases of the central nervous system. There has been noticed a considerable data variability about cortisol level in normal state and in pathological one, however, the majority of articles have detected its connection with clinical manifestations and outcomes of the diseases. The study of cortisol level in cerebrospinal fluid is of a special interest in case of neuroinfections, specifying its direct connection with the disease severity and aetiology that gives new possibilities to develop effective diagnostic criteria. In general, the literature data specifies the advanced study of disorders of hypothalamus-hypophysial-adrenal gland functioning, receptor apparatus of target cells, as well as interrelations of cortisol with immune system in case of infectious diseases to reveal new criteria for diagnostics, course prediction and disease outcome, therapy correction.