A telescopic steering column assembly in which the length of a steering shaft may be adjusted comprising a pair of shafts which are telescopeable while maintaining rotary engagement, a fixed bracket mountable on a vehicle body for rotatably supporting one of said shafts while restricting the axial movement thereof relative to said fixed bracket, a movable bracket which is movable with respect to said fixed bracket for rotatably supporting the other shaft while restricting the axial movement thereof relative to said movable bracket, screw means including A pair of internally and externally threaded members which threadably engage for effecting the relative movement between said brackets and rotary drive means mounted on one of the brackets for imparting the rotary movement to said screw means.