Guide and fastening device for plant support wires, in particular for rows of grapevines, the device having at least one pair of vertical upright elements, fastened to a head pole and provided with longitudinal guides within which are made to slide fastening elements for the lateral containment wires for the growing vegetation. To each pair of upright elements for the lateral containment wires is associated a further vertical upright provided with a guide within which is made to slide a fastening element for at least one carrying wire.