We have studied the levels of hepatic GSH in animals intoxicated with bromobenzene. A marked decrease of hepatic GSH was observed in poisoned rats. Such decrease was prevented by previous administration of lead nitrate, an inhibitor of DMES. In the rats treated with lead nitrate alone a rise in hepatic GSH was observed. Such protection was further observed by histological examination. The mechanism of protection exerted by lead nitrate against bromobenzene intoxication is discussed.