Twenty-four preterm infants with respiratory failure from severe hyaline membrane disease (HMD) received mechanical ventilation at high respiratory frequencies. The average birthweight of the infants was 1244 ± 301 g, and 7 babies weighed less than 1000 g. The average gestational age was 30 ± 2 weeks, and 6 infants were born at 28 weeks or less. The method of ventilation included (1) respiratory frequencies of 60–110/min, sometimes with brief manual ventilation at more rapid rates, (2) peak inflation pressures (PIP) of less than 35 cm H2O, (3) inspiratory durations of 0.15–0.25 sec, (4) positive end-expiratory pressure (PEEP) of 4–9 cm H2O, and (5) weaning from mechanical ventilation by reducing tidal volume until peak inflation pressure (PIP) reached 20–25 cm H2O, whereupon respiratory frequency was decreased. Paco2 was kept at 30–40 torr and Pao2 at 60–80 torr. Of the infants, 22 survived (92%) with few major complications.