Abstract: A height-adjustable table for supporting a patient during medical examination or treatment in which a patient support table top mounted on a carrier 2 is connected to a base 3 by a parallelism maintaining linkage comprising a diamond or rhombus shaped linked assembly of four mutually pivoted equal struts 6, 7, 8, 9, pivotally attached top and bottom to the carrier 2 and to the base 3, and intermediately to the centers of first and second struts 17, 18 which are attached at their ends for free rectilinear displacement, to slides 20, 22, 24, 26, mounted on the carrier 2 and the base 3. Inextensible diagonal links 30, 32 connect diagonally opposed slides 24, 22 and 20, 26, to form an assembly of good horizontal and vertical stiffness even at the maximum height adjustment which is effected by e.g. a screw jack 5.