Abstract: A manually, longitudinally adjustable motor vehicle seat having a lower rail secured to a vehicle chassis, and an upper rail longitudinally displaceable in the lower rail and secured to a seat component. Locking mechanisms released by release mechanisms secure the rails, and assume a release position when the backrest is folded forward. A blocking lever pivotably mounted on a pivot shaft secured to the upper rail can assume two stable extreme pivot positions, namely a passive position where the blocking lever has no contact with the release mechanism, and an active position where the blocking lever blocks the release mechanism in its release position. Upon longitudinal displacement of the seat from a comfort-longitudinal adjustment arrange into an easy-entry-longitudinal adjustment range, a control device comes into contact with the blocking device pivoting against the force of a spring device, out of its passive and into its active position, and vice versa.