This work deals with the study of rheological properties of two types of elastomeric blends. Rheological properties such as shear rate, shear stress and dynamic (shear) viscosity of two types of elastomeric blends with a different compositions were measured. The properties were determined by capillary and oscillating rheometry under laboratory conditions and also by using an extruder under operating conditions. The work was mainly focused on determining of the deviation of elastomeric blends from Newtonian fluid flow, which was determined on the basis of obtained graphical dependences of blends from measured rheological parameters using different types of rheometers and a wide range of shear rates. Since elastomeric blends are considered to be pseudoplastic fluids, the shear viscosity values ​​showed a decreasing tendency with increasing shear rate. Blend 1 has better flow properties and thus processing properties because the deviation from the Newtonian flow is smaller and closer to the ideal fluid flow. Blend 2 contains a higher proportion of natural rubber, and thus shows higher stiffness and poorer processability. This research work has been supported by the Operational Program Integrated Infrastructure, co-financed by the European Regional Development Fund by the project: Advancement and support of R&D for "Center for diagnostics and quality testing of materials" in the domains of the RIS3 SK specialization, Acronym: CEDITEK II., ITMS2014 + code 313011W442.