In a system for controlling a headlight of a vehicle to be controlled, a distance detector detects a distance between the controlled vehicle and an other vehicle ahead thereof. A determiner determines a first target direction for an optical axis of the headlight in a vertical direction when it is assumed that the optical axis of the headlight passes through a target located at the detected distance with respect to the controlled vehicle. The target has a predetermined height above a predetermined reference point. The predetermined height of the target is unchanged irrespective of change in the detected distance. A first adjuster adjusts the direction of the optical axis of the headlight in the vertical direction so that the direction of the optical axis is matched with the determined first target direction.