Abstract: An archery bowstring mounted open notch peep sight apparatus comprising a hollow cylinder having two disc-shaped pieces, one attached to either end of the cylinder, forming one unit, and which has a hollow channel running lengthwise through the center of the peep sight which may receive the tightly fitting bowstring so that the peep sight apparatus may be mounted on the bowstring. In a preferred form the peep sight has a slot extending along its length, to allow the bowstring to pass through so that the peep sight may be easily mounted on a bowstring, even while the bowstring is strung on a bow. When the bow is drawn back the peep sight is thereby tilted along the angle of the drawn bowstring so that in the archer's line of sight the two discs of the peep sight appear to partially overlap in such a manner so that visual notches appear on the right and the left of the point where the discs of the peep sight visually overlap.