Terrestrial insects are most diverse groups of animals and contribute to the biodiversity to a large extent. Light trap sampling is commonly used in insect biodiversity studies. A wide variety of light traps with different light designs are being used. Numerous light sources have been used to access the photo response of the different insect species since last forty years. However, not all the light sources proved efficient to attract and collect all the nocturnal insect species insects in a particular habitat. The success of light traps is affected by a wide variety of factors. Environmental conditions, trap design, height of the light source, attraction radius of a light source, surrounding anthopogenic lights, wave length, intensity of light source, timing and duration of light trap, all affect the success of light traps. Therefore, we are presenting an exclusive review of light trap in a single window system.