The present experiment was conducted to study the effects of organic acids (Ascorbic and Citric) on egg weight loss, hatching performance and embryonic mortality in fertile eggs from Sinai hens. Results showed that : -   Ascorbic acid (10gm/L) dipping treatment for 1 minute (AA1) significantly increased hatchability percentage and significantly decreased all rates of embryonic mortality. -  Ascorbic acid (10 gm/L) dipping treatment for 2 minutes decreased significantly the percentage of culled chicks. -  Citric acid (20 gm/L) dipping treatment for 2 minutes (CA4) had significantly the highest averages of egg weight loss, albumen and amniotic fluid pH, culled chicks also early and late embryonic mortality. while it decreased albumine height embryo weight at the 14th  day of incubation period and hatchability percentage. -  Citric acid (10gm/L) dipping treatment for 1 minute increased significantly embryo weight at 14^th day of incubation period. -  Distilled water dipping treatments increased significantly the rate of piped dead embryos however, it decreased egg weight loss and albumin pH. -  Non-dipped eggs had significantly tha highest rates of albumin height, chick's weight at hatch and unhatched eggs with piped live embryos but recorded the lowest value of aminiotic pH. It is concluded that, dipping eggs in ascorbic acid solution at a concentration of 10 gm /L for 1 minute increased significantly hatchability percentage and decreased embryonic mortality.