Epidemiological studies indicate that intrauterine growth retarded (IUGR) newborn is at a higher risk to asphyxia and hypoxic ischemic brain injury. We conducted ECoG analysis alongside with the measurement of cerebral blood flow (coloured microspheres) and metabolism to compare the responses of growth retarded and normal weight (NW) newborn piglets to severe neonatal asphyxia. Under general anesthesia and mechanical ventilation, 1 day old NW and IUGR piglets were subjected to systemic asphyxia for 1 hr. (S,Oz = 13-17%; paCOz 70-80mmHg), followed by 3 hours of reoxygenation. After ten minutes of asphyxia, CMR02 was not diminished despite a significant reduction of quantitative ECoG parameters in both groups. This indicates a changed relationship between functional and basal cerebral metabolism as a result of asphyxia. There were no differences in the ECoG parameters in the surviving animals of both groups. In addition, the three piglets that died after asphyxia had a poor recovery of cerebral function. It was concluded that computerized quantitative analysis of ECoG together with measurement of cerebral energy metabolism is a sensitive parameter to differentiate between functional and basal cerebral energy metabolism in the asphyxiated newborn.