Abstract: The invention relates to a lighting system intended to light the interior of cabinets of the type used in commercial refrigerators, having glass doors. The system is based on a series of three interconnected LEDs mounted on a printed circuit board (PCB). The assembly is inserted into a diffusion tube, the shape of which enables optimized light emission and is designed for sections installed inside cabinet door frames. The LEDs can be powered by a current or voltage source and the manner in which the LEDs are housed along the inner periphery of the door enables the optimized lighting of the items on display.