Twenty-five samples of maize kernels collected at harvest time from geographically different corn fields in Peru, were examined for the occurrence of toxigenic Fusarium species. The most frequently recovered species were F. subglutinans (48%), F. moniliforme (46%), and F. equiseti (5%). Other Fusarium species isolated (up to 1%) included F. graminearum, F. acuminatum, F. solani, F. oxysporum, and F. culmorum. Assays of Fusarium culture extracts using Artemia salina larvae, showed F. subglutinans as one of the most toxigenic species, and its toxicity was mostly correlated to the capability to produce beauvericin (BEA). All eight tested isolates of F. subglutinans grown on autoclaved corn kernels produced BEA (from 50 to 250 mg/Kg) as well as moniliformin (M) (from 70 to 270 mg/Kg). This is the first report on BEA and M production by maize isolates of F. subglutinans from South America. © 1993 Kluwer Academic Publishers.