A decorative telescoping cap, sleeve and base cover for an office chair center post and base. A tubular plastic sleeve surrounds the upper portion of the height adjustment mechanism cylinder extending above the hub of the metal base. The tubular plastic sleeve has an outwardly flaring shoulder at its lower end which engages and rests upon the central tubular hub of the metal base of the chair. A plastic cylindrical cap telescopes over the tubular plastic sleeve, with the height adjustment mechanism rod of the chair extending through a central opening in the top wall of the cap to engage the cylindrical cap to raise and lower its relative to the tubular plastic sleeve as the height adjustment rod is raised and lowered. A plastic cover is provided for the metal base of the chair, with the cover having a central hub portion which fits over the central tubular hub of the metal base of the chair and arms which fit over the arms of the metal base. The central hub portion of the cover has an inwardly projecting shoulder which fits over and engages the outwardly flaring shoulder of the tubular plastic sleeve to prevent the tubular plastic sleeve from lifting off the hub. The plastic cover is fastened to the metal base.