Abstract: A device for establishing a semi-permanent connection of optical fibres comprises an elastic clamp associated with two retaining clamps which are mounted by attachment means such as clips on a support. The clips when in rest position on the support, are adapted to be brought selectively into a first position wherein the corresponding clamp is held with sufficient force for the fibres to be able to slide above them, and a second position wherein the fibres are blocked in place under the corresponding clamp. To establish the connection a fibre is blocked in position under a retaining clamp and an opposite second fibre slides under the opposite retaining clamp and the elastic clamp until its end abuts with that of the first fibre. Thereafter, the clips of the two clamps are placed in the second position so as to secure the connection.