Abstract: A flexible endoscopic ligating instrument comprises a flexible fiberoptic endoscope on the end of which is secured an outer tube and an inner tube inserted and reciprocally movable within the outer tube. An elastic ring is mounted peripherally on the end of the inner tube which projects beyond the outer tube. A trip wire is fastened to the inner tube to provide rearward motion to the inner tube and thereby cause the elastic ring to slide off and effect ligation. The instrument is particularly suited for ligating lesions deep within the alimentary tract such as esophageal varices.