Polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) belong to the family of persistent organic pollutants (POPs). They are lipophilic, bioaccumulative, and highly stable in the environment. PCBs consist of non-dioxin-like PCBs (PCB-NDL) and dioxin-like PCBs (PCB-DL). They were primarily used in transformers and capacitors starting in the 1930s, and their use was gradually regulated between 1987 and 2013. PCDD/Fs are primarily formed during thermal processes such as waste incineration, industrial activities, or accidental events. Their atmospheric emissions were regulated in 2002 and again in 2010. PCBs and PCDD/Fs have proven toxic properties: the PCB-DL congeners and two PCDD/F congeners have been classified as carcinogens for humans. Furthermore, exposure to PCBs and PCDD/Fs may also have effects on reproduction, the endocrine, immune, and nervous systems. As part of the national biomonitoring program, the Esteban cross-sectional study (2014–2016) measured the levels of 45 PCB biomarkers and 17 PCDD/F biomarkers in the French mainland population among adults aged 18 to 74 years (n=604). Analyses were performed on blood samples for all biomarkers studied. In addition to describing the exposure levels of PCB and PCDD/F congeners, the determinants of exposure to the following groups of biomarkers were characterized: the sum (Σ) of PCB-NDLs, the Σ of PCB-DLs, major PCBs (ΣPCB 138+153+180), indicator PCBs (6 PCB-NDLs and 1 PCB-DL), the Σ of PCDDs, the Σ of PCDFs, the Σ of PCDD/Fs, and dioxin-like compounds (Σ PCB-DL + PCDD + PCDF). Nearly all PCB-NDLs and PCB-DLs were quantified. Six out of seven PCDD congeners were quantified at more than 50%, and four out of ten PCDF congeners were quantified at more than 60%. In the general adult population, PCB and PCDD/F exposure levels were lower in the Esteban study than in previous French studies. The levels of PCB and PCDD/F exposure measured in the Esteban study were equivalent to or higher than those in foreign studies conducted during the same period. Exposure levels to these substances increased with age. Exposure to dioxin-like substances (PCB+PCDD/F) increased with body mass index. The consumption of eggs, fats, and self-produced animal products appears to be a dietary determinant of exposure to PCBs and PCDD/Fs. Consumers of unfiltered tap water appeared to have higher PCB-NDL levels than consumers of bottled water. Among the determinants of PCDD/F exposure are also the use of a barbecue, poor indoor air circulation, the absence of functional ventilation in the kitchen or bathroom, and frequent use of pesticides. The Esteban study thus allows us to highlight a decrease in PCB and PCDD/F exposure, likely linked to the impact of legislation aimed at regulating the presence of these molecules in the environment. However, the population remains exposed to these substances due to their chemical stability, their persistence in the ecosystem, and certain ongoing emissions. Various residual sources that are still not subject to regulation today may be responsible for PCB and PCDD/F emissions: certain types of waste, transportation, the residential sector (e.g., burning of green waste), and the service sector. These sources contribute to the contamination of the entire food chain via soil and water, which continues to expose the French population today through the food chain. Domestic practices (such as using a barbecue or frequent use of pesticides) and poor indoor air ventilation also contribute to PCB and PCDD/F contamination. Given the proven or potential health impacts associated with PCBs and PCDD/Fs, measures to reduce exposure are still necessary to protect the population.