Abstract: A level-indicating device and the method of placing said device inside the shaft of a golf putter. The device is so placed within the shaft so that when the putter is laid horizontal on the surface of the green the device will indicate the exact slope of the green at that point. The device is an insert so constructed as to be inserted into the putter shaft from the top of the shaft (grip end) before the grip is placed on the shaft. It is molded to an exact fit inside the shaft and as the shaft is tapered, it will be properly placed when the top end of the insert is flush with the grip end of the shaft. The lower end of the insert has a cavity just large enough to accommodate a levelling vial. The vial cavity is cast so that when the vial is snapped into the device it will be exactly in the desired position and will be completely protected by the insert.