The presence of mycotoxins in feed for ruminants has been an ongoing problem, but still there is no regular programs monitoring mycotoxin contamination for green fodder, hay or silage. The aim of the study was to assess the amount of aflatoxins and ochratoxin A in dried green fodder (sward), which is a raw material for silages. The three-year study (2008-2010) was carried out in ten organic farms and six conventional farms, focused on breeding dairy cattle. The content of mycotoxins in dried sward and its contamination with moulds depended both on the production system as well as on the year of the study. The highest contamination with moulds was noticed in the first year of the study in sward from organic farms, which averaged 4.54 log CFU / g DM. At the same time the mycotoxin content in the sward was 4.46 ppb in the case of ochratoxin A, 6.20 ppb for aflatoxin B1 and 15.18 ppb in regard to the sum of aflatoxins (B1, B2, G1 and G2). Between 2009 and 2010 the average amounts of ochratoxin A and aflatoxin B1, both from organic and conventional farms, were significantly lower than those in 2008, but no significant difference was observed regarding the amount of total aflatoxins. The average content of aflatoxins and ochratoxin A taken from all years of the study was significantly higher for sward from organic farms than their content in sward in conventional farms. It was found also a positive correlation between the degree of moulds contamination and the contents of examined mycotoxins in forage.