Abstract: A branching device for fibre-optic cables, consisting essentially of two half-casings which can be joined together and contain means for connection to a multi-fibre/fibre-optic unit and means for connection to a plurality of single-fibre/fibre-optic units, the half-casings being shaped to form a cavity arranged to contain a plurality of optical fibres, the cavity being of essentially annular shape and having a width greater than the thickness determined by the plurality of separate optical fibres within the device, the optical fibres within the branching device which connect together the means for connection to a multi-fibre/fibre-optic unit and the means for connection to a plurality of single-fibre/fibre-optic units having a length greater than the length of the minimum development of the annular cavity.