Plant pathogenic Fusarium moulds occur world-wide and cereals can become infected during the growing period. Fusarium was detected in 83 % of 69 cereal samples of batches intended for food or feed production and harvested in The Netherlands in 1993. A considerable genotypic and phenotypic variation was observed within two of the most frequently isolated Fusarium species. Mycotoxins can be excreted in the crop by the fungus after the plant becomes infected. A literature review revealed 137 secondary metabolites that could be, produced by Fusarium species which were isolated from food raw materials. Twelve of those secondary metabolites were identified as mycotoxins based on toxicity observed in test animals. Six of those twelve have possibly been involved in human disease outbreaks (T-2 toxin, nivalenol, deoxynivalenol, acetyldeoxynivalenol, fumonisin B1 and zearalenone). Most of the mycotoxins are stable under process conditions used for food production and can be detected in food. Cereals harvested in The Netherlands in 1993 were contaminated with deoxynivalenol (food poisoning and immunotoxic), 3 %, or zearalenone (oestrogen), 1 %. Fumonisin B 1 (carcinogenic, related to human oesophageal cancer) was detected in 98 % of samples of maize from batches imported in The Netherlands and intended for food production. A 28-day toxicity study on the effects of fumonisin B 1 in rats revealed dose-response related apoptosis in the kidney. The lowest observed effect level was at 0.19 mg fumonisin B 1 kg -1rat body weight. The data on fumonisin B 1 toxicity were used to estimate a tolerable daily intake (TDI) of 500 ng fumonisin B 1 kg -1human body weight. The probability of being daily exposed to fumonisin B 1 at a level corresponding to this TDI was 12 % for the people in The Netherlands consuming the average amount of maize, 55 % for people belonging to the group of 'eaters only' and 78 % for people with gluten intolerance. The health of the consumers in The Netherlands might, in the current situation, be challenged by ...