A vehicular video camera display system includes an interior rearview mirror assembly having a casing and an electro-optic reflective element, with a video display device disposed in the casing behind the electro-optic reflective element. With the interior rearview mirror assembly mounted at the interior cabin portion of the vehicle, a video display screen of the video display device is operable to display video images that are viewable through the electro-optic reflective element by a driver of the vehicle. A rearward-viewing video camera is disposed at a rear portion of the vehicle and views at least rearward of the vehicle. Control circuitry is disposed at the interior rearview mirror assembly. Image data captured by the rearward-viewing video camera is communicated from the rearward-viewing video camera via a twisted pair wire to the control circuitry disposed at the interior rearview mirror assembly.