The invention relates to a vehicle seat comprising a seat part and a backrest, the backrest comprising at least one left-hand backrest longitudinal support extending in the vertical direction of the backrest and at least one right-hand backrest longitudinal support extending in the vertical direction of the backrest, the backrest longitudinal supports being attached to the seat part and/or a seat-part frame in a lower end region and comprising at least one cushion element, wherein the length of a distance between the backrest longitudinal supports can be adjusted by means of at least one elongate backrest cross strut arranged in the upper region of the backrest.