Specific organochlorines (OCS) and chlorophenols belong to the organochlorine (OC) family, which is classified as persistent organic pollutants (POPs). They are lipophilic, bioaccumulative, highly stable, and resistant in the environment. OCS were used in agriculture, wood treatment, and vector-borne disease control starting in the 1940s, and were then gradually phased out between 1980 and 2009. Chlorophenols were also used as biocides in agriculture, as well as in industrial, domestic, and medical applications. Lindane and pentachlorophenol (PCP) are carcinogenic to humans (Group 1), while other OCs are likely (Group 2A) or possibly (Group 2B) carcinogenic. OCs may also disrupt the endocrine system and reproductive, metabolic, and neurological functions, and may be implicated in developmental delays in children as early as the fetal stage. As part of the national biomonitoring program, the Esteban cross-sectional study (2014–2016) measured exposure levels of 18 specific organochlorine biomarkers and 9 chlorophenol biomarkers in the French mainland population among children aged 6 to 18 (n=255 for OCS and n=500 for chlorophenols) and in adults aged 18 to 74 (n=759 for OCS and n=900 for chlorophenols). Analyses were performed on blood samples for OCS and urine samples for chlorophenols. The Esteban study is the first study to measure OC exposure levels in children in mainland France. In adults, a comparison with the ENNS study (2006–2007) revealed lower levels in the Esteban study compared to the ENNS study for the biomarkers examined. In both children and adults, OCS were widely detected, whereas chlorophenols were detected only rarely. OC exposure levels were lower in our study compared to earlier foreign studies (except for β-HCH). For β-HCH, levels were higher in our study than in the other studies (German, Canadian, and U.S.). Six OCS quantified at levels exceeding 60% were analyzed to identify determinants of exposure: pp'-DDE, β-HCH, cis-heptachlor epoxide, oxychlordane, trans-nonachlor, and dieldrin. OCS exposure levels increased with age and body mass index. Consumption of fatty foods, such as eggs, fish, seafood, and fats (oil, butter, margarine, crème fraîche), as well as consumption of fruits and vegetables from all sources, appeared to promote exposure. Consumption of meat, dairy products (milk, yogurt, cheese), as well as foods from the garden, personal livestock, or organic farming seemed to be associated with a decrease in exposure. Exposure via indoor air in homes (poor ventilation, use of personal repellents, and ownership of indoor plants) appeared to be associated with high levels of exposure to OCS. Owning a lawn or living in a suburban neighborhood rather than in the city was associated with higher levels of VOC exposure, likely due to exposure from contaminated soil. Finally, exposure levels were higher among individuals with occupational exposure to dust (plant, animal, or topsoil) and those working in agriculture, market gardening, the sale of flowers and other crops, woodworking and wood processing, and the production or use of pesticides. Given the still-elevated levels of organochlorine pesticide exposure (particularly pp'-DDE and β-HCH), multiple exposures to these substances, and their concerning health effects, it appears necessary to provide the best possible protection for the population.