The invention relates to a piston pump for a vehicle braking system, having a housing section and a piston that is displacably guided into the housing section. A receiving cap is provided for receiving an inlet valve. A sealing element is connected to the receiving cap for sealing the piston and a piston rod that is joined to the sealing element. The piston rod has a first and a second piston rod element. In the first piston rod element, a fluid inlet for introducing the fluid into the inside of the piston is provided. The second piston rod element partially covers the fluid inlet in the axial direction of the piston.