Prediction of physical and thermodynamic properties in polymer manufacturing technology is of profound interest for the design and operation of industrial scale reactor and separation processes. In the present study, the Sanchez-Lacombe and perturbed-chain statistical associating fluid theory equations of state were employed to predict the physical and thermodynamic properties in catalytic olefin (co)polymerization industrial applications. Model predictions obtained by these two commonly used equations of state are compared with a large number of physical and thermodynamic property data over a wide range of pressures and temperatures. Aspen Polymers Plus software package is utilized and all the characteristic pure component and binary interaction parameters employed in the models are reported. The range of applicability in terms of operating conditions for the studied EOS is discussed, and recommendations regarding their use are provided.