A vision system for a vehicle includes a first imager located at a front portion of the vehicle, a second imager located at the rear of the vehicle, a third imager located in a first exterior rearview mirror assembly of the vehicle and a fourth imager located in a second exterior rearview mirror assembly of the vehicle. Responsive to the vehicle being shifted into a reverse gear, (a) video images derived from image data captured by the second imager are displayed on a video display screen and (b) responsive at least in part to processing of captured image data by a common image processor, the driver of the vehicle is alerted to the presence of an object exterior the equipped vehicle. When the vehicle travels forward, the common image processor processes first image data captured by the first imager for at least a lane departure warning system of the vehicle.