Key words:Quail, Broiler Breeder, Incubation, Light, HatchabilityLight influences hatchability efficacy of poultry eggs as well as their productive and reproductive performance. Apparently fertile eggs of Japanese quail and Cobb 500 broiler breeder used in this study and incubated surrounded by dark, red and green light environments in order to investigate their effects on hatchability, embryonic mortalities and egg weight loss during incubation. Results revealed that, Red and Green light had significant increase (P < 0.05) on both scientific and commercial hatchability of Japanese quail and Cobb 500 eggs compared to those exposed to darkness during incubation. Moreover, Red light decreased (P < 0.05) early embryonic mortalities. Total egg weight loss of Japanese quail significantly decreased by application of green and red light color during incubation, Meanwhile, Green light decreased the total egg weight loss Cobb 500 broiler breeder eggs. These results suggested that Red or Green light is possibly the key spectrum to improve hatchability.