Due to the interstitial pulmonary edema present in neonates with idiopatic respiratory distress syndrome (IRDS), it was believed furosemide would be useful in its treatment. In newborns with this syndrome, the effect of said diuretic was studied in blood gases, oxygen alveoloarterial difference and right to left short circuit. Twenty-two infants with similar clinical and laboratory characteristics were included in the study. Out of them, 11 were given furosemide (1 mg/kg/single dosis) and the remaining cases were controls. No difference was shown between both groups in PaO2 and PaCO2 and therefore, the alveoloarterial difference of oxygen nor the right to left short circuit during 60 minutes that the study lasted were either affected even if the infants who were given furosemide showed a significantly greater urinary flow. Due to the above results, the use of furosemide is not recommended for children with IRDS to eliminate an interstitial edema.