Maize silage was sampled to investigate the mycotic flora in it, the material for testing being taken at the time of preparing the silage as well 4 to 5 months later. It was found that richest mycoflora developed in the superficial layers of the silage mass, chiefly constituted by fungus species of the Aspergillus, Penicillium, Alternaria, and Mucor genera. It was also established that Aspergillus fumigatus was the most frequently isolated species. It is believed that the development of the mould fungi in maize silage was dependent on the quality of compaction and air-tight pressing of the ensiled mass.