During the period 1984-1993 just over 1600 samples of agricultural commodities, comprising maize, compound animal feeds, oil seeds, soyabean, fishmeal and forage were examined for fungi and over 20 mycotoxins using a multi-screen augmented with individual assay. Aflatoxin had the highest incidence in over 14% of all samples examined followed by trichothecenes at 10% and then zearalenone at 4%. Since 1989 selected maize samples with high levels of Fusarium spp. have been examined for fumonisin B, and of these (n = 20) in 1993, 90% were positive. Because of this result and high incidence of Fusarium spp. (32%) in maize and maize containing feeds, which was higher than either Aspergillus spp. (27%) or Penicillium spp. (12%), concern is expressed with regard to the potential presence of fumonisin in the food chain.