The distribution of total aflatoxin (AFT) and cyclopiazonic acid (CPA) between conidia and mycelial matrix was studied in five isolates ofAspergillus flavusLink cultured on maize grain for 20 days at 30°C. Total aflatoxin and CPA production differed between the isolates withAspergillus flavusF2R4FP 1–5 producing the most AFT (conidia—0.245 μg/g; mycelial matrix—83 μg/g) and CPA (conidia—0.091 μg/g; mycelial matrix—37 μg/g). The production of AFT and CPA by this isolate was compared in liquid (malt‐extract‐yeast‐extract‐glucose) and solid substrates (yeast extract sucrose agar and maize) at 30°C. The ratio of AFT:CPA in maize decreased from 16.6:1 to 1.6:1 between 7 and 21 days’ incubation. In liquid culture and yeast extract sucrose agar, the ratios were reversed and ranged from 1:3 to 1:9 and 1:22 to 1:28, respectively, the greatest difference in both media occurring after 15 days.