This study was conducted in the field of domestic birds of the Department of Animal Production at the College of Agriculture and Forestry / University of Mosul, and the field study period was from 7/2/2023 to 20/3/2023 (42 days) for the purpose of studying the effect of adding flaxseed oil and animal tallow and the combination between them on the productive performance and nutritional value of broilers. In this study, 288 non-naturalized broilers chicks (type Ross 308) at the age of one day were used in this study. The coefficients of the study were as follows: the first treatment (T1, control) fed on a standard diet (Free of oil and fat), the second treatment (T2) was fed on a diet containing flaxseed oil by 6 %, the third treatment (T3) was fed on a diet containing animal fat by 6 %, and the fourth treatment (T4) was fed on a diet containing flaxseed oil by 3 % with animal fat by 3 %. The results showed a significant increase in vivo weight and weight gain in addition to the relative weight of the thighs, the percentage of visceral fat and the concentration of high-density lipoproteins (HDL-C). besides that, the results also showed a significant decrease in percentage of net and relative weight of the chest, back and wings in addition to glucose concentration. However, there were no significant differences between the coefficients in total feed consumption, nutritional conversion factor, relative weight of neck, heart, liver, gizzard and Fabricia gland.