The purpose of this work was to evaluate the quality of commercial kefir, obtained from the local market. Kefirs produced by eight manufacturers were analyzed. Four of them were classified as factory with large scale of production and signed: D1, D2, D3, and D4. Three kefirs marked: M1, M2, M3 originated from the local dairy cooperatives. One evaluated product signed T1 was sold as cheap brand in hypermarket. Kefirs were evaluated for the sensory properties, chemical composition (fat, protein, total solids, solid non fat - snf), flow curve and area of hysteresis loop between upward and downward curve of stirred kefir. Flow curves were described by two rheological models: Ostwad de Waele, and Casson, the apparent viscosity was calculated as well. Most of the analyzed kefirs were characterized by satisfactory sensory quality, but only the product D2 got the maximal note close to maximal 5.0. Unexpectively kefir D1 obtained from well known brand manufacturer was determined as the lowest sensory quality product. Fat content in evaluated kefirs showed that in three dairies the standardization of fat was done imprecisely. The highest discrepancy between the fat level declared by producer and determined was stated in kefir T1. As a result of protein and snf levels analysis, it was concluded that manufacturers D2, D3 and M2 have done standardization of those components, fortifying milk to 3.93-4.72% of protein and 9.72-11.7% snf. Kefirs D1 and D3 were characterized by the highest value of shear stress in the whole range of shear rate as well as other rheological parameters: consistency coefficient K, yield stress, Cassons viscosity, and apparent viscosity.