This trial was conducted to investigate the effects of supplementing saturated and unsaturated fat sources on serum metabolites and meat physiochemical parameters in the diets of broiler chickens. A total of 360 day-old male broiler chicks (Ross 308) were used in a completely randomized design with five treatments and six replicates of 14 chicks. The assay diets were developed by applying a basal diet with no supplemented fat and the addition of soybean oil (SO), lecithinized palm oil (LPO), a 50 : 50 mix of SO and LPO (ESL), and 75 : 25 mix of SO and LPO (HSL) ratios to the basal diet. The inclusion levels of experimental fats were 2% and 4% in the starter and growing periods, respectively. Blood samples were collected from broilers to evaluate serum biochemical metabolites on day 41. Thigh meat samples were provided and analysed after 1, 5 and 10 days’ storage to evaluate lipid peroxidation at the end of the experiment. Fat and protein contents of thigh muscle and abdominal fat weight were measured and reported. Chickens fed LPO had greater serum triacylglycerol and very low density lipoprotein concentrations compared with those that received other dietary treatments (P <0.05). The fat content of the meat was higher in birds supplemented with SO, LPO and ESL than control (P <0.05). After 5 and 10 days of storage, the values of thiobarbituric acid reactive substance were lower in meat of broilers receiving LPO than SO and HSL (P <0.05). In conclusion, LPO decreased lipid peroxidation during different storage periods compared with SO.