Cerebral utilization rates of glucose and oxygen were measured in 18 conscious, unrestrained neonatal piglets. Cerebral glucose utilization rate was 26.9 ± 2.8 μmol/min/100g (mean ± SEM), cerebral oxygen utilization rate was 160 ± 10 μmol/min/ 100 g and the glucose to oxygen ratio was 1.03 ± 0.11, implying that glucose is the primary substrate for cerebral metabolism in the normal neonatal piglet at rest. These results are similar to the data obtained in the few studies of cerebral metabolism in the human infant and encourage the continued use of the piglet as a suitable animal model.