An illuminated number display device is disclosed which includes a generally rectangular housing having a front wall on which is mounted one or more number plates so that each number plate overlies an opening in the front wall. Each number plate defines a number visible in daylight and has a plurality of frustoconical light passages therethrough which outline the number and facilitate improved illuminated number display at night from a plurality of low energy light bulbs mounted internally of the housing so that the light from each bulb passes through at least two openings in the front wall and through the light channels in the corresponding number plates. Light diffuser plates are preferably disposed between the front wall openings and the light bulbs, and, optionally, over an opening in a bottom wall of the housing to provide downwardly directed auxiliary lighting.