This experiment was carried out using 900 Japanese quail eggs to study the pre and post hatch performance of different eggs weight as affected by light intensity during incubation. Incubating eggs comprising of small (<11g), medium (11-12g) and large (>12) weight categories incubated under the recommended conditions of the chicken eggs with light intensity 20-25 luxes or 40-50 luxes emitted from incandescent bulbs. 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 were observed in hatchability, early dead embryo, piped egg, egg weight loss, embryo weight percentages, hatch time and chick weight or weight loss, which improved in medium sized eggs. Insignificant differences among eggs size groups for egg production, chick sex, culled and chick weight loss. However, highly significant differences were observed in yolk-free body mass and quality scores, which improved in medium sized eggs. In regard to the effect of light intensity, it significant affected hatchability, embryo growth and moisture content of embryo, which improved in eggs incubated with light intensity 40-50 luxes. 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. The incubated light intensity treatment (40-50 luxes) had significantly better chick weight and relative weight gain than light intensity (20-25 luxes). Also, light intensity significantly increased body temperature, chick breast, liver, ovary and residual yolk sac weight at the 1st and 2nd day of age as well as feed conversion and egg production. However, insignificant differences of yolk-free body mass, chick length, culled and chick weight loss, feed consumption and egg quality scores were observed among all experimental groups. Insignificant interactions of incubated light intensity× egg weight groups were existed in most studied traits except in yolk-free body mass, feed conversion and egg production. It could be concluded that the suitable results of pre and post hatch performance were obtained for medium sized eggs of Japanese quail with incubated light intensity 40-50 luxes. Therefore, it could be recommended that intensity treatment (40-50 luxes) could be applied successfully by the hatchery managers to have a better hatch performance without any significant negative effects on chick quality.