Abstract: An open-and-close control device for a horizontally slidable vehicle door fitted with a lock that includes a horizontal endless screw rotatably, movably held within a rail fixed to a vehicle body adjacent the vehicle door, and adapted to be rotated by a rotary electric motor. The horizontal endless screw engages a threaded aperture in a slide translationally movable in the rail, wherein the slide is connected by a single connecting rod to an inner arm positioned on the vehicle door. The arm is oriented towards an inside of the vehicle body such that the single connecting rod is at an angle of less than about 25.degree. to the horizontal endless screw. Opening the vehicle door is initiated by a substantially outward transverse translation of at least part of the vehicle door.