This study was carried out to evaluate the pre and post hatching performance of Fayoumi chicks produced from eggs exposed to high incubation temperature and sprayed with L-Carnitine. A total number of 600 eggs were used and randomly distributed into four groups, each group consisted of three replicates of 50 eggs. The first group served as control without any treatment (C), the second (T1) was exposed to high incubation temperature (40 o ) for 3 hours daily, the 3 rd and 4 th groups (T2 and T3, respectively) were exposed to high temperature (40 o ) for 3 hours at 6 th , 7 th and 8 th of incubation period, and sprayed with L-Carnitine at levels 25 and 50ml /Liter, respectively. Hatchability traits, live body weight (LBW), body weight gain (BWG), feed consumption (FC), feed conversion ratio (FCR) and carcass traits of chicks hatched in all treated group were studied during the period from 0 to 12 weeks of age. Results revealed that LBW, BWG, FC and FCR were significantly (P<0.05) improved in T2 and T3 groups. Chicks in T2 group had the higher (P<0.05) relative weights of liver, gizzard and spleen. From these results, it could be concluded that spraying of L-carnitine at level 25 ml/L after exposure to high incubation temperature (40 o ) during the 6 th , 7 th and 8 th days of incubation for three hours daily from 12 pm to 3 pm markedly improved chick performance post hatching compared with other groups.