This study aimed to evaluate the impact of strain, thermal manipulations during incubation on the productive performance of chickens. A total of 2250 fertile eggs of both Golden Montazah and Dokii-4 eggs produced from hens at 42 week old. The eggs of both strains were classified into 3 equal thermal treatments (2 strains × 3 treatments × 3 replicates × 125 eggs). All eggs were incubated at 37.5°C and 55-60 % RH during the period from one day till hatch and were considered at the control group, while those in the 2nd and 3rd groups were exposed daily to 35 and 40ºC for 3 hours (from 12PM to 3 PM) during 3 successive days (5 to 7 day) of incubation. During the last three days of incubation, eggs were exposed daily to 37 °C and 60-65% RH. The chicks for two strains raised from one-day-old to 16 weeks of age to study the productive performance. The results showed that the chick weight at one-day-old as well as 4, 6, 8 and 16 weeks of age significantly decreased in Dokii-4 chickens, as well as the daily and total body weight gain in the Dokii-4 chicken were significantly decreased during the periods from (0-4), (0-8) and (0-16), Also the daily and total feed consumption during the periods (8-12) and (0-16) significantly decreased in the Dokii-4 chickens as compared with that of the Golden Montazah chickens, While no significant differences between two strains in feed conversion ratio. Referring to the thermal manipulations, the results showed that the chicks body weight at one day old as well as 6, 8, 12 and 16 weeks of age in the 2nd (40°C) group were significantly decreased and the daily and total body weight gain during (0-4), (0-8) and (0-16) were significantly decreased as compared as well as the daily and total feed consumption for chicks produced from eggs exposed high incubation temperature (40°C) during (4-8), (0-8),(8-12),(12-16) and 0-16 weeks of age was significantly decreased as compared with those under 37.5°C (control) and 35ºC (low) groups, but no effect  due to thermal manipulations strains in feed conversion ratio. No significant differences due to the interaction between the strain and thermal manipulations in productive traits. It could be concluded that the productive traits for Golden Montazah chickens produced from eggs exposed to normal and low incubation temperatures improved significantly as compared with those in high incubation temperature group.