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 disposed 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. Image data captured by a rearward-viewing video camera is communicated as a digital signal from the rearward-viewing video camera via a cable to control circuitry disposed at the interior rearview mirror assembly. The video display device displays video images that are derived, at least in part, from image data communicated via the cable from the rearward-viewing video camera to the control circuitry disposed at the interior rearview mirror assembly.