The ‘developmental origins of adult health and disease’ (DOHaD) hypothesis postulates that adverse influences early in development can program the risks for adverse health outcomes in adult life. In modern societies, exposure to man-made environmental contaminants is a potential risk factor for developmental programming of chronic disease. Endocrine-disrupting chemicals (EDCs) are of specific concern. EDCs act by mimicking or inhibiting the actions of endogenous hormones, and can have estrogenic, anti-estrogenic, or even anti-androgenic activity. Most EDCs are synthetic chemicals that enter the environment and persist for long periods of time. Among them are many substances that are in widespread use, including dioxin, plastic-softening chemicals, agricultural pesticides, polychlorinated biphenyls, industrial solvents, and pharmaceuticals. Some evidence suggest that exposure to EDCs during early development can cause long-term health outcomes via mechanisms of epigenetic memory.