Aflatoxins are potent carcinogenic, mutagenic, and teratogenicmetabolites produced primarily by the fungal speciesAspergillus flavus and Aspergillus parasiticus. Foods and feeds,especially in warm climates, are susceptible to invasion byaflatoxigenic Aspergillus species and the subsequent productionof aflatoxins during preharvesting, processing, transportation,or storage (7). Over the last few years, means for mycotoxindetection have been simplified. This is mainly because of theofficial recognition of immunological methods. However, thelevel of mold infestation and the identification of governingspecies are still important parameters which could give anindication of the quality of the material as well as of the futurepotential for the presence of mycotoxins. Mold counts aretherefore included in the quality control assurance of manyfoods. The current methods being used for assessing moldpresence are time-consuming, labor-intensive, and costly; requirefacilities and mycological expertise; and—above all—donot allow the specification of mycotoxigenic strains. Because ofthe toxic and carcinogenic potential of aflatoxins, there is anurgent need to develop detection methods that are relativelyrapid, easily replaceable, and highly specific. PCR facilitates invitro amplification of a target sequence and offers several advantagesover traditional methods of diagnosis: organismsneed not be cultured prior to their detection by PCR; thetechnique possesses exquisite sensitivity, being theoreticallycapable of detecting target DNA molecules in a complex mixturewithout the use of radioactive probes; and it is rapid andversatile (1). PCR is now applicable to detection of microorganisms,including plant pathogens (18). However, no informationis available to date on the use of PCR for the detectionof molds infecting grains and foods, especially mycotoxigenicspecies.