Abstract: A child seat for a motor vehicle is adjustable between a lower retracted state at the normal seat height of the motor vehicle seat, and an unfolded position in which the child seat stands out from the normal seat height for occupation by a child. A frame and a supporting structure are connected and hinge-jointed to each other by front and rear parallelogram arms. At least one diagonal locking brace is hinged on one side to one of the frame, the supporting structure and one of the parallelogram arms, and on an other side is guided by a tranverse part in a longitudinal guide. A locking segment has at least one holding notch to accommodate the transverse part, with flanks extending transversely to the longitudinal guide and a handle for releasing the tranverse part from the holding notch. The handle extends over a region of a front surface of the child seat.