A putter alignment tool for use in establishing a correct line of putting motion of a golf club head upon a golf ball. An elongated structure includes a first guide wall and a second spaced apart and substantially parallel extending guide wall, the first and second guide walls being secured together proximate at least one of first and second ends. A golf ball placement position is located between the guide walls at an intermediate location between its ends. First and second adjustment mechanisms are associated with at least one of the first and second guide walls. The putter head swing clearance adjustment mechanisms include inwardly projecting portions relative to the guide walls and in order to adjust a width and height (swing window) within the structure proximate the ball placement position, the mechanisms permitting unimpeded travel of the golf club head during a putting stroke.