This study was carried out to investigate the effect of inclusion of animal and vegetable fat sources in the broiler diets on their performance. Two sources of fat; vegetable oil (Sunflower oil, SFO) and animal fat (Beef tallow, BT) were tried in two levels (2%, 4%) in four groups of chicks, besides a mixture of both fats (2% for each) was tried in additional group. The diets were
isocaloric and isonitrogenous. Both fat levels (2% &4%) improved growth and feed conversion compared with the control diet but the 4% level was superior in its effect.Birds which had been fed diets containing a mixture from plant and animal fats were significantly higher at 21 & 42 days than those fed either SFO or BT alone. At the same time ,all the three groups recorded heavier weights compared to those fed on the diet supplemented with 2% fat or fed basal diet alone. The same trend was detected for liver weight and abdominal fat percent however the group fed on diet supplemented with 4% SFO recorded the highest value of cholesterol. Total lipids were significantly affected by fat supplementation and the animal fat was the highest in its effect.