A vehicle-onboard driving lane recognizing apparatus of a small scale includes an image pick-up unit (1) mounted on a motor vehicle for picking up images of scenes making appearance in front of the motor vehicle, an image data selecting unit (2) for selecting image data only of a predetermined region from the image picked up by the image pick-up unit (1), an image data storing unit (3) for storing the image data, and a driving lane recognizing unit (4) for detecting lane markings (21) on the road from the image data stored in the image data storing unit (3) to thereby recognize a driving lane extending along the lane markings (21). The image data selecting unit (2), the image data storing unit (3) and the driving lane recognizing unit (4) are all implemented in a single chip.