A ligation tool for endoscope includes an overtube having an insertion lumen 21a made of a flexible material, which permits an insertion portion 11 of the endoscope to be inserted therethrough so as to advance and retreat, an O-ring 22 for ligation attached to a distal end of the overtube, and a operation wire 24 which is locked to the O-ring for ligation, has a distal portion extending to the proximal side of the overtube, and is operated to be pulled or pushed at its proximal side, thereby separating the O-ring for ligation from the tip of the overtube. According to this ligation tool for endoscope, time and effort taken to set the ligation tool for endoscope in the endoscope becomes unnecessary, a sufficient field of vision of the endoscope can be secured, and the curving performance of the tip of the insertion portion of the endoscope does not deteriorate. Furthermore, this ligation tool is also advantageous when endoscopic sclerotherapy is performed together.
