A multi-functional on-vehicle camera system comprises a plurality of cameras mounted on a vehicle and monitors each displaying a camera image. An image processing section is provided for processing images taken by the plurality of cameras. A system control means is provided for selecting a camera image to be processed from a plurality of images obtained from the plurality of cameras based on signals representing vehicle conditions, and for designating a type of image processing performed in the image processing section. The image for assisting the safety driving is displayed at an appropriate timing according to driving conditions in such a manner that the driver can easily grasp the circumferential conditions from the displayed image.