A vehicle head restraint assembly is provided with a first guide member mounted proximate to a vehicle seat back and a second guide member mounted to the first guide member for movement in fore and aft direction. One of the guide members has a series of notches. A head restraint is mounted to the second guide member. A locking mechanism is mounted to the other guide member for extending into one of the notches. A biasing member biases the locking mechanism in engagement with the notches. An actuator is mounted to one of the guide members for actuation from one lateral side of the head restraint and cooperates with the locking mechanism such that linear actuation of the actuator from one lateral side results in symmetrical compression of the biasing member for disengaging the locking mechanism from the notches for permitting fore and aft adjustment of the head restraint.