There were three objectives of this study: to assess the usefulness of microcrystalline cellulose applied as a fat replacer to produce in mayonnaise emulsions of a decreased fat content; to determine the impact of this ingredient added on the physical-chemical and sensory properties of low fat mayonnaise emulsions; and to compare emulsions produced with market products with no microcrystalline cellulose added. Two preparations of microcrystalline cellulose were used: Vivapur MCG 591 and Vivapur MCG 611 manufactured by a company “J. Rettenmaier&Söhne”. These preparations differed in the content of sodium carboxymethylcellulose (Vivapur MCG 611: 11,3–18,8% Na – CMC, Vivapur MCG 591: 9–15% Na – CMC). The microcrystalline cellulose was applied in three various doses: 0,5%, 1%, and 2%. Three types of low fat mayonnaise emulsions were produced using a ‘cold method”, and their fat content was: 5%, 15% i 30%. Based on the results of the investigations performed, it was proved that it was possible to produce low fat mayonnaise emulsions with microcrystalline cellulose added. Owing to the addition of microcrystalline cellulose, low fat mayonnaise emulsions got a high viscosity. And the sensory analyse of consistency confirmed that the final product had a required level of consistency when the microcrystalline cellulose had been added to the mayonnaise emulsions. Also, it was proved that the best consistency was obtained when a Vivapur MCG 611 preparation was added and its dose proportion was 1%.