Aflatoxins are toxic secondary metabolites produced commonly by Aspergillus flavus and Aspergillusparasiticus. In this study, the possibility of using multiplex PCR was investigated to speed up and specifythe detection of aflatoxigenic Aspergillus species in meju, a traditional Korean fermented soybean foodstarter. Two different sets of three primers were designed specifically for the omtB, ver-1, aflR, and omtAgenes present in the aflatoxin biosynthesis cluster. The optimized multiplex PCR showed that onlyaflatoxigenic Aspergillus species gave three band patterns in both primer sets. The detection limits weredetermined as 125 pg/ml for genomic DNA from aflatoxigenic A. parasiticus KCCM 35078, and 105 spores/gof meju sample for DNA extracted directly from meju. A total of 65 Aspergillus isolates from meju weretested for the presence of aflatoxigenic fungi by the application of multiplex PCR, and were analyzed byTLC and HPLC for the aflatoxin production in the culture filtrates. Results showed a good correlationbetween the presence of the aflatoxin biosynthesis genes analyzed by multiplex PCR and aflatoxinproduction by TLC and HPLC. This suggests that this multiplex PCR method may provide an accurate andspecific detection of aflatoxigenic Aspergillus species in fermented soybean foods.