Theoretical and experimental investigations have been made to predict the performance of a backward-curved blade centrifugal pump. A mathematical model based on steady two-dimensional incompressible Navier-Stokes (N-S) equations has been developed. The numerical solution was made using the primitive variables with artificial compressibility. The predictor-corrector method proposed by MacCormack was employed. The use of this technique involved imaginary rows behind walls, and periodic boundaries at far upstream and downstream which adequately improved the convergence to the solution. Based on this model a computer code has been developed and used to predict the flow pattern inside the pump and to determine the pump characteristics. A test rig was used to measure the real pump characteristic at controlled flow rates. Comparison of calculated and measured pump characteristic showed good agreement. Examination of the flow pattern at different flow rates might be useful to interpret the many performance features of the pump.