HFV is a mode of therapy that allows gas exchange with pressure fluctuations much lower than that required for conventional ventilation, and may consequently decrease the incidence of barotrauma and chronic lung disease. At present the National Institute of Health is sponsoring the first large controlled trial to test the efficacy of HFV using an oscillator in premature infants with respiratory failure. Results of this trial will help to clarify some of the indications for HFV and its usefulness in a large number of infants with respiratory failure secondary to RDS.