Abstract: External fixing system (1) for orthopaedic exoskeleton; the fixing system (1) comprises two clamps (2, 6), which have clamping seats (5, 9) and respective knurled elements (13, 14) facing each other, and a spring (12) for pushing the clamps (2, 6) one against the other so that their relative rotation is prevented by the coupling of the two knurled elements (13, 14); in this way, in use, it is possible to obtain locking of the relative position of the clamps (2, 6) while the clamps (2, 6) are tightened by means of an Allen screw (23) arranged in an opposite position with respect to the clamping seats (5, 9).