Studies with aflatoxin B-1, ochratoxin A, zearalenone, deoxynivalenol, and fumonisins B-1 and B-2 added at various stages of the brewing process show that these mycotoxins (or metabolites) may be transmitted from contaminated grains into beer, Citrinin does not survive the mashing step, Mycotoxins in beer could originate from the malted grain or from adjuncts, Although high incidences and concentrations of aflatoxins and zearalenone have been found in local beers brewed in Africa, aflatoxins have not been detected in European beers, Zearalenone and alpha- or beta-zearalenol (the metabolite likely to occur) have not been found in Canadian and European beers, except for one sample analyzed by thin-layer chromatography only, Ochratoxin A rarely has been detected at >1 ng/mL in beer; liquid chromatographic methods with a 0.05-0.1 ng/mL detection limit, however, have shown moderately high incidences of trace levels, Deoxynivalenol, which survives the brewing process, has been found with high incidence in Canadian and European beers, with concentrations of >200 ng/mL reported in several German beers, Fumonisins B-1 and B-2 occur to a limited extent in beer.