Abstract: A guard device is designed to be fitted around a signpost to provide a barrier against persons attempting to climb the signpost. A pair of mating guard members each have a mating edge for engagement with the mating edge of the other guard member, and the mating edges each have a central recess forming an opening with the other recess for fitting around a signpost. Fastener devices such as bolts secure the guard members together with the opening in gripping engagement with the signpost. The guard members when secured together form a continuous barrier surface projecting outwardly from the signpost.