Abstract: A vehicle driving assist system includes at least a first camera (1) located at a rear part of the vehicle (10) for capturing a first field of view (11) outside of the rear of the vehicle (10). The first field of view (11) is larger than a second field of view (12) covered by a transflective element (22) of an optional rear-view mirror (21). The system further includes: a display (2) configurable for displaying an image of the first rear field of view (11) captured by the at least one, first camera (1); processing means for modifying the image to be displayed by the display (2) and for overlaying on the image displayed by the display (2) at least a reference line (41, 51, 52, 52?) which corresponds to a predetermined distance at ground level (40) from the driver's ocular points (42) or from the rear of the vehicle (10).