Abstract: The invention is a device for aiding a golfer to properly stroke the ball with a putter. In detail, the invention comprises a support member for detachably mounting to the gripping portion of the putter at substantially the end thereof. A generally linear arm is rotatably attached to the support member which, when in use extends outward from the shaft in a direction at right angles to and in the opposite direction of the striking surface of the putter. The arm being rotatively mounted, can be rotated downward in alignment with the longitudinal axis of the shaft when storing the putter. Preferably, a detent is incorporated which releasably positions the arm in the extended position or the retracted position.