Approximately 50 samples of poorly stored cereals were examined for mycotoxins, fungi and biological activity. While some mycotoxins such as ochratoxin A and citrinin occurred frequently, many other fungal metabolites present could not be identified. Cereal extracts and isolates of some fungi, when grown in culture, were often toxic to brine shrimp larvae but, in some toxic extracts, no known mycotoxins were identified. A preliminary report of this study forms the subject of this paper.