Abstract: A ligating instrument for forming ligatures in anatomical structure at an internal operative site in the body includes an elongate instrument body having a distal end for positioning at the operative site, a proximal end for positioning externally of the body and a lumen between the distal and proximal ends, a length of filamentous ligature material disposed in the lumen and forming a plurality of contractible ligature loops having knotting elements movable along the length of ligature material to contract the ligature loops and an operating member movable relative to the length of ligature material to move the knotting elements to contract the ligature loops. The ligature loops are withdrawable through the distal end of the instrument body for positioning around anatomical structure at the operative site. The operating member is movable, from externally of the body, to move the knotting elements to contract the ligature loops around the anatomical structure to form ligatures.