In this study, lipid peroxidation and antioxidant status were investigated in children with acute bacterial meningitis and encephalitis. The aim was to determine whether there was a possible role of free radicals in meningitis and encephalitis in childhood. Our study included 16 children with acute bacterial meningitis, 13 with encephalitis, and 17 control subjects. Serum malondialdehyde (MDA), reduced glutathione (GSH), vitamin C, vitamin E, beta-carotene, and retinol levels were studied in all subjects within 6 h of admission. There was a statistically significant difference for serum MDA, GSH, and vitamin C between the groups. Serum MDA and vitamin C levels were higher, and serum GSH levels were lower in the study groups compared to the control group. Vitamin C levels were similar in both the encephalitis and control groups, but they were significantly lower in the children with encephalitis than the meningitis group. In conclusion, our study showed that serum MDA and GSH levels were affected in children with both meningitis and encephalitis, but vitamin C level was affected only in children with meningitis. Serum vitamin E, beta-carotene, and retinol levels were not changed in childhood meningitis and encephalitis.