A vehicular video camera display system includes an interior rearview mirror assembly having a casing and an electrochromic reflective element, with a video display device disposed in the casing behind the electrochromic reflective element. With the interior rearview mirror assembly mounted at the in-cabin side of a windshield of a vehicle, a video display screen of the video display device is operable to display video images that are viewable through the electrochromic 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 as a digital signal from the rearward-viewing video camera via a cable to the control circuitry disposed at the interior rearview mirror assembly.