Table eggs belong to the one of most important components of our daily diet, being a natural source of vitamins and proteins but unfortunately also of chemical contaminants. Free range poultry, as well as other animals, are very good bioindicators of environmental contamination. Together with the feed and soil, laying hens pick up different pollutants and store them in their tissues and organs. These accumulating toxic substances are also excreted into birds’ eggs. Therefore egg consumers may constitute a group at risk because intake of contaminants may exceed toxicological reference values, set to protect their health. Thus this chapter focusses primarily on sources and toxicity of dioxins and PCBs, human exposure, risks associated with their presence in food and eggs, and safety of the food chain. Data on other toxic substances of concern in eggs are also presented.