Abstract: An pillow with a height adjustment device comprising a driving mechanism consisted of an axle, two driving gears spaced on the axle, and a knob coupled to the axle at one end, and two rack assemblies meshed with either driving gear and disposed beneath the cover cushion of the pillow, each rack assembly being consisted of a first rack and a second rack, slidably mounted in and extend through two guide tubes horizontally meshed with the respective driving gear at different height, the guide tubes being adapted to curve upwards at the outer portion of which so as to guide and support the first and second racks curved upwards at the portions near the end of the racks attached to the cover cushion to lift the cover cushion as the axle is turned by the knob in one direction; the first and second racks of each rack assembly will thus be moved downwards to lower the cover cushion as the axle is turned by the knob in the reversed direction.