This study was conducted to determine the harmful effect of oxidized oils on lipid metabolism in broilers. In total, 100 one day old broiler chicks were used in the study. Animals were equally divided into a control and an experimental group. All broilers were fed with isocaloric and isonitrogenic rations ad libitum. The broilers in the control group were fed a good quality vegetable oil and the broilers in the experimental group were fed an oxidized vegetable oil. The study was run over 42 days. The blood samples were collected at the end of 3(rd) and 6(th) weeks. Blood parameters of lipid metabolism were analysed in serum samples.