In this study, the flow rate, velocity, head, and power in a designed and manufactured centrifugal water pump were studied and determined experimentally. The effect of the impeller with different blades on the centrifugal pump performance has been investigated. Three different impellers with 4, 5, and 6 blades are tested to determine the number of the optimum blades. The experimental results showed that the flow rate, velocity, heat, and power are higher for the case of the impeller with 6 blades than that for the two cases of 4 and 5 blades. The losses decrease by increasing the number of the blades due to the reduction of the secondary flow for a certain limit. The experimental results showed better centrifugal water pump performance when an impeller with 6 blades is used.