ABSTRACTThe incidence of moniliformin (MON) producing Fusarium spp. in selected corn (Zea mays L.) samples from Mexico and the United States and the effects of alkaline cooking and the tortilla manufacturing processes on the reduction of MON were determined. The percentage of infected kernels with Fusarium spp. ranged from 0 to 22% in eight foodgrade corn samples, including six from Mexico and two from the United States. Complete (100%) reduction of MON was observed when a naturally contaminated corn sample containing 1.4 μg of MON/g of corn was used in a pilot‐scale alkaline cooking and tortilla manufacturing process. In a companion laboratory‐scale study, using a cultured corn sample containing 17.6 μg of MON/g of corn, a 71% reduction of the toxin was observed during the process. Alkaline cooking appeared to be an effective method for reduction of MON in corn.