Eleven day old Sprague-Dawley (CD strain) rat pups whose mothers were maintained on a 200 mg/l dosage of lead (Pb) acetate in their drinking water from breeding and through gestation until the pups were weaned exhibited differences in a learning paradigm as compared to controls. No significant differences were noted between the control pups and the experimental pups with respect to acquisition rates but there were significant differences between the two groups with respect to extinction rates. Similar results were obtained in tests of rat pups whose dams had been maintained on a 400 mg/l dosage of lead (Pb) acetate. These data indicate that low level lead (Pb) exposure can induce significant behavioral deficits in young rat pups.