Administration of a single dose of lead nitrate (200 mg/kg) to pregnant rats (Day 18 of gestation) resulted in the appearance of destructive brain changes in their offspring on postnatal Day 40, including the cysts, foci of glial cell proliferation, pyknosis of neurons, decrease of NADH- and NADPH-diaphorase activity in neocortical and hippocampal neurons. The reduction of both neuronal density in the cortex and cortical thickness was also demonstrated. The intensity of free radical oxidation in the cortex was increased 3-fold, while the concentration of lipid hydroperoxides was increased 3.9 times, and the resistance to peroxidation was decreased by a factor of 3, which is indicative of oxidative stress. Possible mechanisms of the pathological changes development are discussed.