A support is provided for attachment to an internal rear-view mirror made from plastic material or lightweight metal for a portable device having a telephone or GPS display screen or for generally electronic, electrical or other devices. The support includes a hooking member shaped to engage with another part of the rear-view mirror, the upper edge thereof, via two hooks, located to either side of a ball pin attaching the rear-view mirror to the windscreen. The hooking member is formed in part from a plurality of links articulated by hinges, in the manner of a metal watch strap. The hooking member is started by a hook-shaped link that secures to the upper edge of the rear-view mirror, followed by a series of links, varying in number, so as to match and constrain the shape of the rear-view mirror, and is finished by two leg feet that form a slide.