Carcinogenic contaminants appearing in food are of external origin or arise in technological processes. The most important of them are nitroso compounds, heterocyclic amines and polycyclic aromatic hydrocarbons. Their occurrence in food is considerably influenced by humans and is typical of certain groups of foodstuffs. Monocyclic aromatic hydrocarbons usually occur only exceptionally as water contaminants. The carcinogenic potential of polychlorinated aromatic compounds, organic chlorinated pesticides and phthalates is small but they show other negative effects on health. The objective of the article is to give an overview of these contaminants, their carcinogenic effects, and their probable amounts consumed in food.