In the present study, effects of non-Newtonian fluids on the characteristics of a centrifugal pump which was designed at 3300 rpm and 40 l/min for water were examined numerically. A numerical analysis using Computational Fluid Dynamics methodology was carried out. Water and three different non-Newtonian fluids of CMC 0.4%, CMC 0.3% and CMC 0.2% which derived from Carboxy Methyl Cellulose (CMC) solution were used in the analyses. The analyses were performed with the flow rates range of 10-80 l/min and rotor speed values of 3300 rpm and 1400 rpm. The results showed that the performance of the pump with non-Newtonian fluids was better than the water at 3300 rpm, contrary to 1400 rpm.