Fructose-1,6-bisphosphate (FBP) has been shown to attenuate central nervous system injury in adult animals. We evaluated whether FBP given after an ischemic-hypoxic insult is protective to the developing brain in a neonatal rat model of hypoxia-ischemia. Postnatal day 7 rat pups were subjected to focal ischemia followed by global hypoxia and then administered either FBP or saline intraperitoneally. A dose of 500 mg/kg or greater of FBP significantly reduced the amount of injury such that 55% of FBP- vs. 17% of saline-treated rats had no injury; 6% of FBP- and 47% of saline-treated rats had severe damage (P = 0.004). There was less infarcted brain in FBP-treated rats (12 +/- 11% vs. 37 +/- 32%; P = 0.005); and fewer FBP-treated rats had > 30% ipsilateral cortical injury (12% of FBP- vs. 50% of saline-treated rats; P = 0.002). FBP lowered serum calcium levels during the first 24 h after the insult without significant changes in ionized calcium or osmolarity. These results indicate that FBP treatment administered systemically after hypoxia-ischemia reduces CNS injury in neonatal rats.