Hydraulic efficiency of the centrifugal pump is mainly depends on mass flow rate, Head and RPM. Finding the best combination with the above said parameters and the best geometry of the pump is possible by using three dimensional CFD simulations.For designers, prediction of operating characteristics curve is most important. All theoretical methods for prediction of efficiency merely give a value; but one is unable to determine the root cause for the poor performance. Due to the development of CFD code, one can get the efficiency value as well as observe actual behavior and the root cause for poor performance by using CFD Analysis of equipment. Author considered 8/6 AH pump for the three dimensional fluid flow analysis and validated the pump hydraulic efficiency with the experiment results. It is observed the behavior of the hydraulic efficiency with respect to the pump performance characteristics. Centrifugal pumps should be run at best efficiency point. Generally the radial force developed on the shaft will be high, if operates away from the BEP and it may leads to shaft damage. So it is important to find out best efficiency point.