The case of preterm, male infant (27 Hbd) with extremely low birth weight (868 g) and Respiratory Distress Syndrom is presented. Despite prolonged artifi cial ventilation (with High Frequency Oscillation Ventilation and FiO2 =100%), dopamine continuous iv infusion) on 30th day of life he started to deteriorate dramatically and the risk of chronic lung disease appeared. On the 32nd day of life Dexamethasone therapy was started. Post initial therapy his condition began improving clearly. This resulted in a successful extubation on the seventh day of Dexamethasone treatment. Breathing with C-PAP (FiO2=34%, Sa02 = 100%) was started. Dexamethasone was gradually reduced, its total cumulative dose was 4.52 mg/kg. The revision of bibliography related with corticosteroids application in preterm infants with chronic lung disease is presented.