The aim was designed to determine the impact of oxidative stress (OS), induced by hydrogen peroxide (H2O2), on the ketorolac plasma concentration and pharmacokinetics in the chicks. A significant decrease was observed in the total antioxidant status (TAS) measured on day 7th, 10th, and 14th of chicks age by 39, 29, and 41%, respectively in comparison to the control (H2O) group. By measuring the analgesic median effective dose (ED50), Ketorolac’s analgesia has been amplified 16% in the stressed (H2O2) group. Ketorolac concentration in plasma was investigated at multiple measured times of 0.25, 0.5, 1, 2, 4, and 24 hours after the administration (14 mg/kg, IM) to 110.38, 181.46, 66.24, 13.08, 10.11, and 4.12 µg/ml at the H2O group and significantly elevated in all times measured except 0.25 and 24 h after ketorolac administration by 24, 38, 54, 199, 93, and 59 % to be 136.45, 250.88, 102.03, 39.13, 19.55, and 6.55 µg/ml in the H2O2 group, respectively. The values of AUC0-∞, AUMC0-∞, Cmax, and Kel in the stressed chickens that were administered ketorolac were elevated by 59, 19, 38, and 43%, respectively, whereas other parameters like MRT, t1/2β, Vss, and Cl were reduced by 25, 30, 56, and 37% respectively compared to H2O group. The results showed the H2O2-induced OS amplified the analgesic action of ketorolac in a chick model; besides its modification of the plasma concentration and pharmacokinetics of ketorolac.