Abstract: A golf swing training device for guiding the shoulder turn of a golfer from the address position to the apex of the back swing, through the forward swing until contact with a ball, and follow-through. In a preferred embodiment it comprises: an elongated rigid the shaft (10). A plurality of first fastening sides of a fastening pair (20) are affixed to one side of the shaft (10). A plurality of second fastening sides of said fastening pair (30) are affixed to the front of a shirt like garment (40) along a horizontal axis running through the mid-sections of the garment's (40) shoulder areas and under the clavicle area. The shaft (10) is then connected to the garment (40) by the engagement of the first sides of the fastening pairs (20) to the second sides of the fastening pairs (30). A flat based marker (50) is located and affixed to a front area of each of the shoulder areas of the garment (40) above the attached shaft (10).