A sign panel holding system of the type used by real estate agents or the like, comprising a normally upright post and two holding members securable to a post at virtually any point of the overall length thereof. The holders are each provided with at least one but preferably two parallel transverse members defining a pair of parallel slots. The lower holder has the slots turned upwardly to engage lowermost edges of a pair of normally generally rectangular panels. The upper holder is positioned upside down and is slideably adjusted along the post to grip the top edges of the panel to thus secure the panels fixedly to the associated post. The advance in the art is particularly in structural simplicity of the device and in its versatile use with panels of different size. The invention also allows the placement of the panels at selectively different levels of the post.