A vehicle periphery monitoring apparatus is comprised of a camera installed in the front or rear of a vehicle, for picking up images of side view of the vehicle; a feature point detecting section that detects feature points in the side images and calculates the motion vectors of the detected feature points; a moving object detecting section that detects a set of a plurality of feature points approaching the vehicle in the side images as an approaching object based on the calculated motion vectors of the feature points; a feature point tracking section that tracks the feature points of the detected approaching object; and a passage time calculating section that calculates the time at which the approaching object passes the front or rear of the vehicle from the feature points of the approaching object tracked by the feature point tracking section.