Abstract: A training device which a golfer can attach to his putter to assist him in developing putting proficiency. The device consists of a rigid annulus having a flat back surface and a concave conical front surface that meet to form the inner edge of the annulus, the diameter of which is smaller than that of a conventional golf ball but large enough to permit the ball to contact the face of a putter to which the training device is attached without also contacting any part of the annulus. Attaching wings projecting in opposite directions from the annulus have flat back surfaces that are coplanar with the back surface of the annulus, to facilitate attaching the training device to a putter.