Abstract: The invention concerns a device for adjusting the height of a tennis court net designed to adapt a net (11), initially adjusted in height for a doubles match, into a net adjusted in height for a singles match. The device according to the invention is characterized in that it is composed of two flexible cables (4) and (5), fixed, by one of their ends, to one of the posts (1), at two distinct points (A) and (B), and, by the other of their ends, to the stake (2) that is associated with it, at two distinct points (C) and (D), and in that the length of the aforementioned cables and the position of their fixation points are adapted to guarantee, on the one hand, the positioning of the stake (2) at the regulation distance from the singles line and, on the other hand, its verticality. It is characterized also in that the cables (4) and (5) are adapted to serve as support to at least one advertising sign (12).