Mycotoxins produced by mould fungi can enter into the human food chain directly through foods of plant origin (cereal grains), consumer goods (coffee and bear) and indirectly through foods of animal origin (kidney, liver, milk and eggs). Mycotoxins occur in small amount in the foods; however their continuous intake even in microdoses can result in accumulation in the organism. Synergic effects of the mycotoxins as well as their possible additive multi-toxic effects seem to be especially dangerous. Mycotoxin problems are very important in Hungary because these natural toxins occur mainly in those cereals (e.g. wheat, maize) that amount to high proportion of the sowing area in Hungary and provide the main foods to the inhabitants. Public health risks of the toxins accumulating in the human and animal bodies during the long term consumption of the mycotoxins containing foods--even in small doses--have not been evaluated yet as thoroughly as their importance would require. However, there are more and more direct and indirect expressions of the danger resulting from the toxins. The most frequently observed human health effects are carcinogen effects (aflatoxin, ochratoxin A, fumonisins, patulin); effects causing developmental abnormalities (zearalenon, ochratoxin); effects harmful to the reproduction (zearalenon, and trichotecenes), effects decreasing the resistance; immunosuppressive effects (trichotecenes), and effects causing injury of the nervous system (ochratoxin A, fumonisins). Prevention of the injury of the health caused by mycotoxins can be completed by joint and integrated activity of the various disciplines only and requires a comprehensive interdisciplinary cooperation. This paper gives a discussion on health injuring effects of the most frequently occurring mycotoxins that are very important from human health aspects in Hungary; on their occurrence in the foods and on their human risk.