There is provided a steering control device for a vehicle of a new structure utilizing a ball screw mechanism for compacting the structure. The steering control device for a vehicle includes a first input shaft 1 connected to a handle, a second input shaft 2 connected to a motor 8, an output shaft 3 connected to a steering wheel, a first transmission 6 for rotating a nut 5 in accordance with the rotational motion of the first input shaft 1 so as to transmit the rotational motion of the first input shaft 1 to the rotational motion of the output shaft 3, and a second transmission 7 for moving the nut 5 linearly in the axial direction with respect to the output shaft 3 in accordance with the rotational motion of the second input shaft 2 so as to transmit the rotational motion of the second input shaft 2 to the rotational motion of the output shaft 3. The center line of the second input shaft and the center line of the output shaft are aligned on substantially the same straight line.