A vehicle height adjustment device includes a jack chamber for supporting a spring receiver supporting a suspension spring's one-side end portion and a fluid-pressure driving unit for supplying/discharging an operating fluid into/out of the jack chamber and elevating up/down the spring receiver. The fluid-pressure driving unit includes a pump for selectively supplying the operating fluid to a first or second channel and a tank connected to the first or second channel not receiving an operating fluid's supply from the pump. The vehicle height adjustment device further includes a jack channel allowing the first channel and the jack chamber to communicate with each other, a valve body closing the jack channel, capable of opening/closing, a spring for urging the valve body in a direction for shutting off the jack channel, and a pilot line for having a second channel's pressure act on the valve body so the jack channel is opened.