A total of 900 eggs from Bandarah and Gimrnizah hens were used in this study to determine the effect of egg weight on some hatchability traits, chick weight, shell thickness, hatchability 96, embryonic mortality, mal position and non-hatched pipped eggs (dead in shell). The results can be summarized as follows: 1.Weight of hatched chick was increased as egg weight increased in both Gimmizah and Bandarah eggs. On the other hand, there were no significant differences in respect of chick weight% between different classes. 2.Bandarah eggs had significantly higher hatchability % than Gimmizah eggs. Although there were no significant differences among Bandarah egg weight classes in hatchability %, but medium egg weight of Gim‌mizah had higher hatchability 95 than both large and small eggs. 3.There were no significant differences in shell thickness due to hen strain or egg weight classes. However, non-hatched eggs had thicker shell eggs than hatched eggs. 4.Percentages of non-hatched pipped eggs showed the major efect on the non-hatched eggs 93.99, 93.29% from the total non-hatched eggs for Gimmizah and Bandarah, respectively. 5.Early embryonic mortality played a second role in decreasing hatcha‌bility, it recorded 6.57, 5.74% from the total non-hatched Bandarah and Gimmizah eggs, respectively. 6.Mal position embryos had very low effect in lowering hatchability % in the two strains. It can be concluded from this study that medium Gimmizah eggs had significantly higher hatchability % than both large and small eggs, but in Bandarah, egg weight had no significant effect on the percentages of hatchability. further studies are necessary to determine the factors that resulted to lowering percentages of non-hatched pipped eggs and early embryonic mortality.