A seat device for a vehicle adapted to adjust a positional height of a seat cushion includes rails, frames supporting the seat cushion, link members, a torque rod connecting link members, a sector gear formed so as to operate together with one of the link members and rotatably supported by one of the frames, an elongated hole formed on the sector gear, a pinion gear meshing with the sector gear, a pressing bracket supported by the pinion gear, a stopper pin inserted into the elongated hole of the sector gear and connected to the one of the frames at a first end of the stopper pin and to the pressing bracket at a second end of the stopper pin.