To date, there is only one small observational uncontrolled study about the use of NHFOV after extubation in preterm infants. Other relatively small case series or retrospective cohort studies suggested safety, feasibility and possible usefulness of NHFOV and have been reviewed elsewhere.The only randomized trial published so far compared NHFOV to biphasic CPAP,in babies failing CPAP and it has been criticized for methodological flaws and for not taking into account respiratory physiology.An European survey showed that, despite the absence of large randomized clinical trials, NHFOV is quite widely used, at least in some Countries and no major side effects are reported, although large data about NHFOV safety are lacking. This may be due to the relative NHFOV easiness of use but evidence-based and physiology-driven data are warranted about this technique.