The aim of this study was to determine the impact of selected modified atmosphere packing variants on microbiological and physicochemical changes of grated Mozzarella cheese during its storage. The study involved microbiological and physicochemical determinations as well as organoleptic evaluation of grated Mozzarella cheese. The study material included samples of grated Mozzarella cheese obtained under industrial conditions and contaminated with microbiological inoculum of foreign microflora. The samples of cheeses were packed into bags using the following conditions: under N₂, CO₂, lowered pressure at 400 mbar, 50% CO₂/50% N₂, 70% CO₂/30% N₂. Microbiological analysis of the cheese samples involved determination of total count of microorganisms, coliform count, yeast and mould count. Physicochemical analysis of the cheese samples involved determination of water content, fat content, total nitrogen content, titratable acidity, pH. Sensory evaluation of the cheese samples was also performed. A significant effect decreasing the development of microflora in the samples of Mozzarella cheese packing in the atmosphere of CO₂ compared to packing under lowered (400 mbar) air pressure and in the atmosphere N₂ was observed. The sensory evaluation of the grated Mozzarella cheese after 4 weeks of cold storage did not reveal any statistically significant difference between the packing variants employed. Reduced pressure air packing guarantees the quality comparable with that obtained by packing under the atmosphere of nitrogen, carbon dioxide or a mixture of these two gases, although too high a reduction of pressure (400 mbar and below) may result in clumping of the pieces of Mozzarella cheese during storage.