A vehicle surrounding monitoring system includes an image-capturing portion, a storage portion, a display-image generation portion, and a display portion. The image-capturing portion captures the image of at least a portion of the area surrounding the vehicle. The storage portion stores the image captured by the image-capturing portion. The display-image generation portion generates a synthesized image for display using a latest image that is captured by the image-capturing portion, and a previous image that is captured before the latest image is captured. The synthesized image is displayed on the display portion. The display-image generation portion decreases the level of visibility of an image region relating to the previous image, according to an elapsed time after the previous image is captured.