Abstract: An actuating mechanism (4), for a longitudinal adjuster (1) of a vehicle seat, includes an upper rail (2.1) and a lower rail (2.2), which rails are lockable to each other by at least one lock (3). The actuating mechanism (4) includes an actuating arm (4.1), a release lever (5), a positioning element (5.2), which is arranged on the release lever (5) and is mounted pivotably at a free lever end (5.3) of the release lever (5), and a connecting region (5.1) which is arranged on the release lever (5) and has an opening (5.4) provided for the non-rotatable fastening of the actuating arm (4.1). The free lever end (5.3) is configured for arrangement in an interior space (I) of the rails (2.1, 2.2). The connecting region (5.1) is configured so as to be able to pass through an upper side of the upper rail (2.1).