In view of the known sensitivity of the developing central nervous system to pollutants, we sought to assess the effects of exposure to uranium (U) - a heavy metal naturally present in the environment - on the behavior of young rats and the impact of oxidative stress on their hippocampus. Pups drank U (in the form of uranyl nitrate) at doses of 10 or 40 mg.L(-1) for 10 weeks from birth. Control rats drank mineral water. Locomotor activity in an open field and practice effects on a rotarod device decreased in rats exposed to 10 mg.L(-1) (respectively, -19.4% and -51.4%) or 40 mg.L(-1) (respectively, -19.3% and -55.9%) in compared with control rats. Anxiety (+37%) and depressive-like behavior (-50.8%) were altered by U exposure only at 40 mg.L(-1). Lipid peroxidation (+35%) and protein carbonyl concentration (+137%) increased significantly after exposure to U at 40 mg.L(-1). A significant increase in superoxide dismutase (SOD, +122.5%) and glutathione peroxidase (GPx, +13.6%) activities was also observed in the hippocampus of rats exposed to 40 mg.L(-1). These results demonstrate that exposure to U since birth alters some behaviors and modifies antioxidant status.