A driving assistance device includes a guide line detecting unit, a remaining distance acquiring unit, and a braking control unit. The guide line includes a base-point mark which is provided at a position which is separated a first distance from the scheduled stop position. The guide line detecting unit detects the base-point mark at a measurement position of a captured image and sets the detected position of the base-point mark at the measurement position of the captured image as the center of the base-point mark in an extending direction of the guide line when the base-point mark is detected at the measurement position of the captured image. The remaining distance acquiring unit acquires the remaining distance on the basis of the position of the base-point mark set by the guide line detecting unit.