The study was designed to evaluate the effect of egg and shell weights on hatchability parameters, embryonic mortality, malposition, chick quality traits and progeny subsequent growth performance of Japanese quail. A total number of 600 eggs were used in this experiment, where150 eggs were taken to initially evaluate egg quality traits. However, the remaining 450 eggs were accurately weighed and divided into 3 experimental categories (N = 150) according to egg and shell weights, namely SEW and LSW (11.24 g vs. 1.86 g), MEW and MSW (13.05 g vs. 1.87 g), and LEW and HSW (14.46 g vs. 1.98) as average. Each group was subdivided into 3 replicates each with 50 eggs (n = 50). The results showed that LEW recorded (p≤0.05) a significant superiority in most of egg quality traits compared to SEW or MEW. However, the highest fertility and hatchability percentages were observed for MEW compared to SEW or LEW. Obviously, there is a strong coefficient correlation of the hatchability parameters due to egg and shell weights. Medium-sized eggs resulted in best chick quality traits with better post-growth performance (p≤0.05) than chicks produced from SEW or LEW. Also, there was a significant positive coefficient correlation (r = 0.72) between egg weight and hatch chick weight (p≤0.05). In conclusion, this study is important in giving information about Japanese quail eggs, where MEW are recommended to obtain better hatchability, lower embryonic mortality and obtain the best progeny subsequent growth performance compared to SEW or LEW.