Abstract: A telescopic flagpole comprises at least two concentrically disposed tubular segments that are axially movable with respect to each other. A locking device housed within an inner segment includes a pin that is biased to extend from the inner segment through a hole in the adjacent outer segment to prevent relative axial movement of the segments. Additionally, a screw mounted in a bushing at one end of an outer segment can be tightened against, passed into, or passed through a portion of the adjacent inner segment to inhibit relative axial movement of the juxtaposed segments. The screw can have an uncommon head configuration to reduce the possibility of unauthorized or unintentional loosening of the screw. Relative rotation of adjacent segments is inhibited by providing an outer segment with an inwardly projecting ridge that engages a notch in the adjacent inner segment. Alternatively, the ridge can engage a notch in a plug inserted into the end of the adjacent inner segment.