A manual vehicle seat reclining mechanism and seat assembly incorporating the reclining mechanism is disclosed. A guide plate and a pivotal plate are assembled together and disposed between the seat base and seat back. A cam is biased by a spring to hold locking elements in engagement with the pivotal plate. A control plate is manually rotated with the cam to release the locking elements by drawing pins on one side of the locking plates radially inwardly with slots provided in the control plate. Ribs are provided on the pivotal plate that prevent the locking elements from returning to the locked position in certain radial alignments of the pivotal plate relative to the guide plate.