A lesion identification system for surgical operations has a light marker adapted for placement in the vicinity of a lesion inside an organ of an organism, and a location-identifying device detecting a light emitted from the light marker at an outside of the organ for identifying a location of the lesion. The marker includes a light emitter and an engagement member associated with the emitter to be engageable with a wall of the organ. The engagement member includes a clip. The light emitter emits light with a wavelength in a near-infrared range. The device includes an endoscope comprising an inserter section having an image pickup element picking up a reflected light, involving the light from the light marker, at an outside of the organ, and an image pickup unit allowing the reflected light, picked by the image pickup element, to be generated as an image for display on a monitor.