Following a report of lead exposure among children attending a school in Seine-Saint-Denis, France, a screening program for childhood lead poisoning was organized in May 2015. The environmental investigation consisted of an assessment of the presence of lead using X-ray fluorescence and its accessibility, as well as a measurement of acid-soluble lead in floor dust. A simulation of expected blood lead levels was performed using the IEUBK model (Integrated Exposure Uptake Biokinetic Model for Lead in Children). The population included in the screening comprised 332 exposed children, aged 3 to 11 years. Environmental measurements revealed lead accessibility in the school setting; 27.9% of dust samples showed a surface lead concentration exceeding 100 μg/m². The geometric mean of modeled blood lead levels ranged from 29.7 to 34.6 μg/L for an average surface lead concentration in school dust ranging from 265 to 354 μg/m². However, the geometric mean of measured blood lead levels among the 275 (82.8%) exposed children who participated in the screening was 13.5 μg/L [12.8;14.4], which is comparable to the general population. Three blood lead levels exceeded the poisoning threshold of 50 μg/L. The geometric mean of the 199 blood lead levels among the included students aged 3 to 6 years was 13.8 μg/L [12.9;14.8]. This screening program serves as an example of managing childhood lead poisoning stemming from a specific environmental issue.