Oxidative stress is implicated in the pathogenesis of numerous disease processes including diabetes mellitus atherosclerosis, ischaemic heart disease and rheumatoid arthritis. Chemical modification of amino acids in protein during lipid peroxidation results in the formation of lipoxidation products which may serve as indicators of oxidative stress in vivo.Selenium as an important antioxidant trace element was found to affect lipid peroxidation and play a role in prevention of diabetic complications.For that we performed a study measuring the lipoxidation products in the form of malondialdehyde (MDA) and selenium level and other routine investigations in 20 complicated type 2 DM subjects, and 20 non complicated diabetic subjects and to age, sex matched 10 healthy subjects.The findings of this study are consistent with the role of lipid oxidation in diabetic complications by finding increase lipoxidation products in diabetic complicated patients. And also the role of selenium as an antioxidant in prevention or delayed diabetic complication. In summary lipid oxidation and antioxidant trace elements e.g. selenium play an important role in prevention of the development and progression of macrovascular complication in type (2) diabetic patients.