Abstract: A repair tool for ball marks on golf greens is mounted on the grip end of a putter. The tool comprises a disc-like base mounting a cylinder on its periphery that is formed with blades which project away from the putter. The blades taper to points at their free ends for easy insertion into the soil about a ball mark. The adjacent sides of adjacent blades slope inwardly away from each other to define cutting edges on their outer periphery and plowing surfaces effective to plow soil which has been loosened by the cutting edges inward upon rotation to fill the ball mark/dent. An expandable fastener having an upper surface is inserted through the grip into the hollow end of a putter shaft for securely mounting the tool in place, the lower end of the cylinder also engaging the grip.