The present invention relates to a sealing device for optical fiber, comprising in combination a plurality of conical jaws (4) with which optical fiber (1) is in line, a body including a corresponding female cone (3) intended to receive the jaws, a nut (6) screwed on the body so as to compress the jaws, a casing (10) linked to the body and covering the nut so as to form around it an at least partly confined volume, a filling material (9) intended to fill at least part of the volume, and wherein the material comprises solid fillers favouring sealing between the body, the jaws and the fiber.