The present device is an illuminated building block device that mimics the look of a laser. The building block includes a non-opaque body comprising at least two mechanical connectors. At least two electrically independent conductors each traverse the body from each connector to each other connector. At least one LED is electrically connected to at least two of the electrical conductors. With at least two building blocks mechanically connected, a power source may be applied to one of the connectors of one of the building blocks to illuminate each LED. Preferably, the body of the building block is generally transparent and is capable of transmitting light from a colored LED to a connected block, thus mimicking the look of a laser. The invention also comprises a set of building blocks that permits light from an LED to pass from one connected block to an adjacent connected block.