The invention relates to an apparatus for mounting a sighting mechanism on a handgun, with a bracket (2), comprising at least a fixed bracket element and a rotatable bracket element (5) opposite thereto that is rotatable on an axis (20) relative to the bracket (2), which is adjustable by an operating element (19) opposite the fixed bracket element (3). To enable a precisely repeatable and low-wear mounting, the operating element (19) is rotatable relative to the rotatable bracket element (5) on the axis (20) thereof.