SummaryInfants born to mothers who have received narcotic analgesics or general anaesthetics often show respiratory depression. By serial analysis of arterialized capillary blood samples it was observed that the maximal effects in terms of pH, Pco2 and base excess values occurred at 10 minutes after birth in a group of babies who had only normal routine resuscitation. In another similar group of babies, in addition to the routine resuscitation measures, 0.5 to 3.0 mg./kg. of doxapram hydrochloride was injected into the umbilical vein immediately after the first sample of blood was taken. It was seen that doxapram–treated infants had less fall of pH and no rise of Pco2 at 10 minutes after birth. The pHand Pco2 values, however, returned to normal physiological limits by 4 to 24 hours in both groups, though the doxapram–treated group had a faster recovery. Further analysis of the data showed that the optimum dose of doxapram was 2 to 3 mg./kg.