In this experiment, we aimed to recorded the effect of chronic oral exposure to DEHP on lipid peroxidation and histopathological lesions induced in different organs. A total of 150 quail chick divided into two groups (75 quail’s chicks at each group), control group left without any treatment all time, the second group was orally administrated 5% of DEHP (278.05 mg/kg bw) three times per week and lasted for 60 days. At 30 and 60 days old, a total number of 25 from both groups were euthanized. Blood samples were collected to determine the serum concentration of DEHP and mono ethyl hexyl phthalate (MEHP), liver and kidney to estimate tissue concentration of malondialdehyde (MDA), samples from different organs for histopathological examination. The result showed that the concentration of DEHP and MEHP in blood's serum and concentration of MDA in liver and kidney significantly increased with time in comparison with the control group; besides, oral administration of DEHP induced sever pathological lesions, in brain, aorta, intestines, liver, lung, ovary and testis. In conclusion, the DEHP and its metabolic product MEHP significantly increased in serum and cause significant increase in concertation of MDA in liver and kidney tissues, produces a significant histopathological change in brain, aorta, liver, intestine, lung, ovary and testis that can cause a life-threatening condition.