In this study, the effects of monochromatic lighting on egg weight loss, embryonic mortality, hatch window and hatching performance were investigated. The number of eggs used in the experiment was a total of 780 (Ross-308 genotype). Eggs were randomly assigned to 3 groups. 1) Control group: Eggs were incubated in dark, 2) Green light group: 560 nm (wavelength from 535 to 585 nm), 3) Red light group: 670 nm (wavelength from 640 to 690 nm). During the first 18 days of the incubation period, continuous illumination of 0.1-0.2 lx intensity was provided with LEDs placed on both sides of the trays. The light transmission was prevented by blank trays coated with greenhouse covering material which has 75% shading feature placed among experiment groups. In this way, light transmission to other trays and any possible hitches of air circulation was prevented. There was no difference between examined egg weights of the treatment groups in the experiment, but it’s found that significant difference in egg weight loss for both colours of light. Red light and control groups (15.00% and 11.92%) show a similar embryonic mortality rate, while the green light group has a lower embryonic mortality rate (5.00%) than these groups. The effects of monochromatic lighting on the hatching time were significant (Chi-square<0.05). Although there was no significant difference between hatching performance parameters of the control and red light treatment groups in the experiment, the green light group had better hatching efficiency than the other groups. The findings of this research were carried out with two different light wavelengths are remarkable for showing that the significant effects of the monochromatic illumination on hatching results.