Context: Epidemiological studies and animal models demonstrate that endocrine-disrupting chemicals (EDCs) contribute to cognitive deficits and neurodevelopmental disabilities. Objective: The objective was to estimate neurodevelopmental disability and associated costs that can be reasonably attributed to EDC exposure in the European Union. Design: An expert panel applied a weight-of-evidence characterization adapted from the Intergovernmental Panel on Climate Change. Exposure-response relationships and reference levels were evaluated for relevant EDCs, and biomarker data were organized from peer-reviewed studies to represent European exposure and approximate burden of disease. Cost estimation as of 2010 utilized lifetime economic productivity estimates, lifetime cost estimates for autism spectrum disorder, and annual costs for attention-deficit hyperactivity disorder. Setting, Patients and Participants, and Intervention: Cost estimation was carried out from a societal perspective, ie, including direct costs (eg, treatment costs) and indirect costs such as productivity loss. Results: The panel identified a 70-100% probability that polybrominated diphenyl ether and organophosphate exposures contribute to IQ loss in the European population. Polybrominated diphenyl ether exposureswereassociated with873 000(sensitivity analysis, 148 000to 2.02 million) lost IQ pointsand3290 (sensitivity analysis, 3290 to 8080) cases of intellectual disability, at costs of£9.59 billion (sensitivity analysis, £1.58 billion to £22.4 billion). Organophosphate exposures were associated with 13.0 million (sensitivity analysis, 4.24 million to 17.1 million) lost IQ points and 59 300 (sensitivity analysis, 16 500 to 84 400) cases of intellectual disability, at costs of £146 billion (sensitivity analysis, £46.8 billion to £194 billion). Autism spectrum disorder causation by multiple EDCs was assigned a 20-39% probability, with 316 (sensitivity analysis, 126-631) attributable cases at a cost of £199 million (sensitivity analysis, £79.7 million to £399 million). Attention-deficit hyperactivity disorder causation by multiple EDCs was assigned a 20-69%probability, with 19 300 to 31 200 attributable cases at a cost of £1.21 billion to £2.86 billion. Conclusions: EDC exposures in Europe contribute substantially to neurobehavioral deficits and disease, with a high probability of >£150 billion costs/year. These results emphasize the advantages of controlling EDC exposure.