Since trace element abnormalities have been found in the human epileptic population, trace element concentrations were determined in blood and tissues of genetically epilepsy-prone rats both exposed to an unexposed to seizure-inducing stimuli and in genetically related epilepsy-resistant rats. Half of the epilepsy-prone group were exposed to seizure-inducing sound twice daily for 3 weeks. Food intake and weight gain were monitored for each animal. Genetically epilepsy prone rats with induced seizures consumed significantly less food and gained less weight than did the epilepsy resistant group. Seizure prone rats without seizures consumed the same amount of food as the resistant rats but gained less weight than the resistant strain but more than the seizure-induced animals. Epilepsy-prone animals had significantly altered trace element concentrations in tissues as compared with the resistant animals independent of seizure induction. Brain and liver iron, liver copper, and brain and heart manganese levels were all significantly lower in the seizure-prone rats as compared with the seizure-resistant rats. In the seizure-prone rats, induction of seizures resulted in an increase in brain and heart zinc levels and a decrease in whole blood manganese levels. These results demonstrate that both genetic factors relevant to susceptibility to seizures and the seizures themselves are associated with changes in trace element concentrations.