Abstract: This experimental was conducted to determine the effects of the dietary animal fat and vegetable oils on performance and lipid metabolism in serum of laying hens. Two hundred Isabrown hens at 67 weeks of age were randomly divided into five groups containing 40 hens each therefore there were five dietary treatments groups, control group (CO) was fed basal diet without fat supplementation. Experimental groups were offered diets having 4 % tallow (TO), 4 % mixture of tallow and flaxseed oil (1:1) (MTFO), 4 % sunflower oil (SO) and 4 % flaxseed oil (FO) respectively. Fat supplementation effected laying performance and serum lipid parameters were significantly (p< 0.05) different among groups except for egg weight. Fat supplementation improved egg production, feed intake and feed efficiency in experimental groups compared with control group. Whereas egg weight was not affected of fat supplementation. Serum high density lipoprotein cholesterol (HDL-C), was significantly higher in group fed FO diet than others, hovewer, triglyceride (TG), total cholesterol (TCOL), and lipoproteins (low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C) levels were found significantly lower than other groups. These results suggest that dietary FO may be valuable ingredient to layers for reducing serum TCOL, LDL-C, VLDL-C, and TG and increasing serum HDL-C levels without any adverse effect.