The actuating device for a vehicle brake system comprises a force input member, which can be coupled to a brake pedal, and a brake master cylinder. The brake master cylinder has at least one force transmission member. The force transmission member is coupled to the force input member in an articulating fashion. The force transmission member is positioned to transmit a force, which has been exerted onto the force input member, to the brake master cylinder. The actuating device has at least one elastically deformable positioning element. The at least one positioning element produces a holding force with which the at least one positioning element holds the at least one force input member in an installation position relative to the brake master cylinder.