Field commodities are exposed to fungal contamination with potential negative impact on human health. Bioactive plant molecules, as for example antioxidant compounds present in common buckwheat (Fagopyrum esculentum Moench), can provide natural means of biocontrol. To this purpose, the ability of flavonols extracted from common buckwheat hull to modulate, in in vitro conditions, Aspergillus flavus production of aflatoxin B1 (AFB1) was tested in comparison to synthetic rutin. Positive results achieved let infer that the extract could be furtherly tested also in vivo. Copyright� (2017) by the International Measurement Confederation (IMEKO). All rights reserved.