Moulds and associated mycotoxins are important factors adversely affecting foods produced using contaminated plant products or animal products derived from animals fed on contaminated feeds. Mycotoxins are toxic to humans and animals, which explains the major concern of food and feed industries in preventing them from entering the food chain. Prevention is essential since there are few ways to completely overcome problems once mycotoxins are present. Toxin-producing moulds may invade plant material in the field before harvest, during post-harvest handling and storage and during processing into food and feed products. Thus, toxigenic fungi have been roughly classified into two groups (i) field fungi; (ii) storage fungi. The Fusarium genus, e.g. F. verticillioides (formerly F. moniliforme), F. roseus, F. tricinctum and F. nivale, are ubiquitous soil organisms, which may infect cereals directly in the field thereby, increasing fumonisins, trichothecene, and zearalenone levels (depending on the species) during growth, ripening of grain and at harvesting. Fusarium sp. can have deleterious effect on plants and decrease plant productivity. Many species can infect heads of wheat and other small grain cereals in fields causing head scab or blight (FHB). Ear rot also can be caused by Fusarium sp. growing on maize. Furthermore, fungi can grow on the non-grain part of plants producing large amounts of mycelium towards the stem where it colonizes the vascular bundles, which inhibits the transfer of nutrients in the upper part of the plant. On the contrary, Fusarium sp. does not significantly contribute to the storage fungi or to the fungal contaminants found only on damaged grains. Due to the multiple possible origins of fungal infection, any prevention strategy for fungal and mycotoxin contamination must be carried out at an integrative level all along the food production chain. Three steps of intervention have been identified. The first step in prevention should occur before Abbreviations: FHB, Fusarium head blight; HSCAS, hydrated sodium calcium aluminosilicates; QTLs, quantitative trait loci * Tel.: +33 4 73 62 40 54; fax: +33 4 73 62 46 59.