Polychlorinated biphenyls (PCBs) were or are manufactured as commercial products. The chemical stability and lipophilicity of these compounds, and their resistance to degradation results in their persistence in the environment and bioaccumulation in animal organisms by entering of various food chains. Food, especially of animal origin, is regarded as a major source of these chemicals for man. Acute toxicity of PCB is low. However, when absorbed in low doses over longer time periods they can cause changes leading in chloracne and other hypo- and hyperplastic responses, endocrine disorders, hepatotoxicity and porphyria, reproductive toxicity and carcinogenesis. Infants fed with breast milk are at greatest risk. The health risk assessment for environmental exposure to PCB was also discussed.