The occurrence of zearalenone in whole plants and parts of maize usually used for silage making was investigated during the cultivation period of the crop.Zearalenone was detected upto several hundreds of μg/kg DM, that mainly accumulated at the end of the ripening process thus contaminating the silages subsequently. The highest concentrations of zearalenone were observed in the leaves especially at the bottom of the plant, which may correlate with leaf necrosis increasing towards harvest. Further research is needed to clarify health risks for farm animals due to uptake of contaminated feed and possible carry-over of zearalenone and its metabolites into the food chain of man.