This study was performed to evaluate the role of using Curcuma longa L. (turmeric) against thermally oxidized oil-induced hematological, biochemical, and histopathological alterations. Eighty male rabbits were randomly divided into 4 groups (20 of each) and treated for 90 days as follows: The first one was kept as standard control group. Groups 2 and 3 received Curcuma longa (CL) 13 g/kg, 5% thermally oxidized oil to ration separately, where the last group was supplemented by CL together with the thermally oxidized oil. Blood samples were collected via ear veins from all rabbits for hematological and biochemical markers analysis. After 30 days, there were non-significant changes in hematological parameters in all groups. The third group exhibits a considerable increase of ALT, AST, ALP, bilirubin, urea, creatinine, uric acid, total cholesterol, triglycerides, LDL-c, and MDA with a considerable decrease in HDL-c and CAT, while the second and fourth groups display non-significant deviations in the previous parameters. Where at 90 days, the third group showed a significant diminution in the RBCs count, PCV, Hb concentration, and MCHC with increase in the MCV and MCH. The fourth group shows a significant increase in levels of total cholesterol, triglycerides, and LDL-c with a significant decrease in HDL-c. Microscopically at 30 days, liver, kidneys, and spleen showed severe degeneration and necrosis which were increased at 90 days that confirm hemato-biochemical findings. It was achieved that CL demonstrated protective effects of C. longa against thermally oxidized oil-induced toxicities. These ameliorative effects are attributed to the inherent phytochemical constituents of turmeric. Therefore, turmeric and its derivatives should be a regular constituent of our diets. Also, turmeric may be exploited as an adjuvant in the phytotherapeutic management of some toxicities.