Polyethersulfone (PES) is extensively used for the preparation of hollow fiber membrane contactors; these modules are utilized in microfiltration (MF), ultrafiltration (UP), and gas separation. Viscosity plays a crucial role in the fabrication of hollow fiber membranes and their separation performance. In this study the effect shear rate, temperature, and polymer composition on shear stress of dope solutions prepared from PES polymer, dissolved in 1-methyl-2-pyrrolidone (NMP) solvent, is experimentally investigated. An empirical equation is developed to describe these effects on the shear stress of the polymer solutions. Data were obtained for (0.050, 0.10, 0.15, 0.20, and 0.25) mass fractions of PES polymer in NMP solvent at temperatures for (298, 308, 318, 328, 338, and 353) K. The shear stress results calculated by the developed equation describe well the set of experimental data.