In developing countries, lead-acid battery factories are one of the heaviest consumers of lead. Due to lead's toxicological properties and prevalent working conditions in such factories, workers are subject to high exposure and health risk. This study discusses results obtained by lead exposure assessment of workers from a Rio de Janeiro battery factory, in light of Brazilian legislation and recent scientific data. Evaluation methods used were environmental (personal air sampling) and biological (determination of lead in blood, Pb-B) monitoring, showing a high personal exposure both in air (>0.1 mg/m³) and blood (55% of Pb-B >25µg/dl). These results confirmed the inefficiency of current control measures, with a possible 46% of workers presenting a Pb-B range of 25-60 µg/dl in risk areas. Recent data suggest that Pb-B levels above 25 µg/dl are related to subclinical alterations in human body that should be investigated during clinical examination. Finally, we propose a strategy based on environmental and biological monitoring to prevent both clinical and subclinical effects.