Disclosed is a vehicle surroundings monitoring device provided with a movement direction determining unit (20) which determines, on the basis of the changes in the position of an object detected by means of a laser radar (8), whether said object is moving in the travelling direction of the vehicle itself or in the intersecting direction which is orthogonal to the aforementioned travelling direction. A classification determining unit (21) executes: on the object that was determined to be moving in the travelling direction, a first classification determination processing in which the object is determined to be a four-wheel vehicle when the size of the object, which is obtained from the detection position by means of the laser radar (8), is within an Al range; and, on the object that was determined to be moving in the intersecting direction, a second classification determination processing in which the object is determined to be a four-wheel vehicle when the size of the object, which is obtained from the detection position by means of the laser radar (8), is within a B1 range.