The value of carnitine in the prevention of cerebral edema due to acute severe hypoxia in 38 newborn mice was studied. Twenty-nine animals received normal saline (0.25 ml) or carnitine (16 mmol/kg) intraperitoneally, thirty minutes before exposure to 0% oxygen in inspired air for two minutes. Nine mice received no drug and were exposed to room air. After hypoxic insult, brain water content was measured and was found to be similar in all groups. These findings suggest that carnitine pretreatment does not prevent brain edema associated with cerebral hypoxia in newborn mice.