An imaging system for a vehicle includes an imaging array sensor and a control. The imaging array sensor comprises a plurality of photo-sensing pixels and is disposed at an exterior rearview mirror assembly at a side of the vehicle with a field of view exterior of the vehicle. The imaging array sensor is operable to capture an image exterior of the vehicle. The control may process the captured images and may determine that the imaging array sensor is misaligned when the imaging array sensor is disposed at the exterior rearview mirror assembly at the side of the vehicle. The control, responsive to a determination of misalignment of the imaging array sensor, may at least partially compensate for the determined misalignment of the imaging array sensor.