The invention relates to a method for operating a piston pump with a differential cylinder drive (1) with at least two differential cylinders (2, 3) for driving at least two conveying pistons movable in conveying cylinders, each conveying piston being driven via an associated differential cylinder (2, 3) of the differential cylinder drive (1) for operating the piston pump, with a hydraulic circuit (4) for driving the differential cylinder drive (1) by the action of hydraulic fluid. The invention also relates to a piston pump for carrying out the method.