Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in human fat and milk samples arise from a variety of sources. It is generally assumed that food intake is mainly responsible for the presence of these contaminants in man. Data on levels in food samples are, however, relatively rare. This review reports the levels found in various foodstuffs which are easily obtained in daily life. From the data, it is clear that most animal foodstuffs have already been contaminated by these contaminants, even though in very small amounts. However, the plant products are free of most PCDDs and PCDFs. It is difficult to evaluate the different sources of contamination of food, but municipal solid waste incinerators and chlorophenol industries are likely to be the most important sources. © 1990.