OBJECTIVE: To determine whether the elective (commencing soon after initiation of mechanical ventilation) use of HFJV as compared to CV in ventilated preterm infants with RDS decreases the incidence of chronic lung disease (CLD) without adverse effects. METHODS: Systematic search in accordance with Cochrane reviews. All randomized controlled trials of elective HFJV vs CV in preterm infants <35 weeks GA or <2000 gms with RDS were included. Data analyses were conducted according to the standards of Neonatal Cochrane Review Group using relative risk (RR) and number needed to treat(NNT) or harm (NNH). Preplanned subgroup analyses were trials with surfactant, high volume strategy (HVS), low volume strategy (LVS) and infants of different gestational ages and birth weight. RESULTS: Overall analyses of the three trials included in the meta-analyses1–3, showed that HFJV is associated with a reduction in CLD at 36 weeks post menstrual age (PMA) in survivors [RR 0.58 (0.34, 0.98), NNT 7 (4, 90)]. Home O2, only assessed in one trial3, is reduced [RR 0.24 (0.07,0.79), NNT 5 (3,21)]. For PVL overall RR is 1.24 (0.59, 2.61); in the subgroup where LVS was intended2 the RR is 5.0 (1.19, 21.04), NNH 4.0(2.3,14.5). In the overall analyses there were no significant differences in incidence of IVH all grades and grades 3 or 4, or in neonatal mortality. Subgroup analyses of infants at different gestational age and birthweight could not be performed. CONCLUSIONS: Overall analyses show a benefit in pulmonary outcomes (CLD at 36 wks PMA,2,3 home O2,3) in the group electively ventilated with HFJV. Of concern is the significant increase in PVL in one single centre trial which used LVS. There are as yet no long term pulmonary or neurodevelopmental outcomes from any of the trials. Until further studies ascertain the most appropriate strategy to ventilate preterm infants with HFJV safely, routine use of HFJV cannot be recommended for ventilated preterm infants with RDS.