A seat slide device for an automotive vehicle which supports a seat to be slidably movable in the front and aft direction. The seat slide device is provided with a seat rail connected to the seat which is slidably connected with a floor rail. A bracket is integrally connected to and vertically projects and extends from the floor rail. The bracket is fittingly connected to a vehicle body with bolts. The bolts are located at a position where they are uncovered by other parts of the device, thereby enabling the easy detachment of the seat from the vehicle body.