This study aimed to evaluate the impact of thermal manipulations during early embryogenesis on hatching traits, physiological re-sponses and productive performance of Matrouh chickens. A total of 675 eggs were divided as follow as (3groups×3replicates×75 eggs). In the control group, eggs were incubated at 37.5°C and 50–55% RH from 0 until hatching. Eggs in the 2nd and 3rd groups were daily ex-posed to (40.0°C and35°C) for (E5-E7) days for 3 hours. The highest hatchability (%) was recorded in control, followed by the 35°C and 40°C groups. The EEM(%) in the (40°C) significantly increased compared with those in the (control and 35°C) groups. The cloacal temperatures for chicks produced from eggs exposed to 40°C were significantly increased than those in the control and low groups. The chicks body weight at 1day, 8and 16wks of age in the high group were significantly decreased compared with those of the control and low groups. It could be concluded that the %) and body weight for chicks produced from eggs exposed to (37.5°C and 35°C) improved significantly compared with those in (40°C) incubation temperatures group. It could be recommended that the short term low thermal stress during early embryogenesis improve chick weight for Matrouh chicks.