This experiment was carried out using 800 Japanese quail eggs to study the hatch performance of different eggs weight as affected by light pulses during incubation. Incubating eggs comprising of small (<10.5g), medium (10.5-11.5g) and large (>11.5g) weight categories incubated under the recommended conditions of the quail eggs with light pulses or without. The obtained results showed insignificant differences among eggs size groups for late dead embryo, dead in shell, chemical composition of embryo and chick quality scores. However, highly significant differences in hatchability, early dead embryo, piped egg, egg weight loss, embryo weight percentages, hatch time and chick weight or weight loss. In regard to the effect of light pulses, it affected hatchability, embryo growth and moisture content of embryo. However it is not significant differences in dead embryo, dead in shell, egg weight loss, hatch time, chick weight or weight loss, chick quality scores. Insignificant interactions of incubated light pulses × egg weight groups were existed in most studied traits. It could be concluded that the suitable results of hatchability and hatch performance were obtained for medium sized eggs of Japanese quail with incubated light pulses.