The use of effective silage additives is increasingly important. The aim of the work was to assess the quality of maize silages treated with BioStabil Mays (BSM) – Silage Inoculant. Only minimal differences in nutritional values of fresh forage between treatment and Control without silage inoculant was observed, even after fermentation of 42 and 91 days. BioStabil Mays treated silage had significantly lower pH compared to Control after 7 days of fermentation, tended to reduced Ammonia (%) levels after 42 days of fermentation, resulted in higher content of LAB and yeast and significantly reduced dry matter losses by 33 % after 92 days of fermentation. The trial confirmed that BioStabil Mays improves aerobic stability by 35.6 h after 42 days of fermentation.