A length-adjustable column for chairs or the like comprises an upright tube with a longitudinal axis and a piston-and-cylinder unit radially supported and displaceably guided in the direction of the longitudinal axis. A lengthwise end of the piston-and-cylinder unit is locked by means of an axial bearing on a base plate of the upright tube in the axial direction. For this purpose, the axial bearing is axially fixed to the lengthwise end of the piston-and-cylinder unit. The axial bearing has at least two locking arms which lock it to the base plate of the upright tube, and a securing bolt which is pushed by the piston-and-cylinder unit between the locking arms to secure the locking.