An adjustable tailgate support contains a fixed inner tube, which is connected to a lower housing part and on which is arranged a spiral spring. The spiral spring on the one hand is supported at the lower end on a setting element held on the inner tube and, on the other hand, is held fixed at a remote, upper, free end in the upper housing part. An increase or reduction in the spring force of the spiral spring can be set by turning the setting element, which has a supporting ring, on an external thread of the fixed inner tube.