In this paper the effect of microwave radiation on the epiphytic microflora, fermentation and silage quality of brome grass (Bromus inermis) is reported. Microwave treatment reduced the initial count of epiphytic microflora, inactivated plant proteases and increased the amount of water-soluble carbohydrates (mainly xylose) in the plant. The damage to the epiphytic microflora was compensated for by the addition of a silage inoculum containing lactic acid bacteria. Microwave treatment reduced protein and beta-carotene loss during ensiling, thereby contributing to the preservation of the nutritional value of the silage.