In order to provide a hydraulic actuating system for actuating a parking lock of a motor vehicle, which hydraulic actuating system manages with as few components as possible which are simple, robust, relatively insusceptible to faults and inexpensive, with a simultaneously low installation space requirement, and the hydraulic layout of which hydraulic actuating system makes a simple actuation and a simple movement possible for locking and unlocking the parking lock, it is provided that a pumping device which can operate bidirectionally with a locking delivery direction and with a releasing delivery direction is used as pumping device, and check valves are arranged in the hydraulic circuit in such a way that, by way of actuation of the pumping device in the locking delivery direction, the parking lock moves into the locked position and, upon actuation of the pumping device in the releasing delivery direction, the parking lock moves into the released position.