This article describes the theoretical analysis and experimental verification of the influence of variations of leakage flow as well as ideal flow on delivery pressure ripple in a balanced vane pump. The analytical model for simulating the delivery pressure ripple of the pump is simplified. It is composed of only the ripple of the ideal flow based on the theoretical pump displacement determined from geometrical pump dimensions, the leakage flow variation dependent on the pump dimensions including clearances and pump-operating conditions, an oil chamber volume in the pump and the impedance of a hydraulic circuit with a throttle valve set close to a pump outlet. The purpose of this study is to predict the pump delivery pressure ripple at the design stage of the vane pump. This article reveals that the delivery pressure ripple can be theoretically predicted through the calculations of the leakage flow as well as the ideal flow. The waveform of the delivery pressure ripple calculated agrees well with the measured one. The leakage flow variation significantly affects the delivery pressure ripple and it can be also calculated accurately from the pump dimensions including the clearances and pump-operating conditions. In addition, the components of the leakage flow are clarified and their effects on the delivery pressure ripple are investigated.