ABSTRACTActive smokers are exposed to reactive free radicals that are present in cigarette smoke. Oxygen free radicals,including superoxide, hydroxyl radicals, peroxyl radical hydrogen peroxide and singlet oxygen, are highly reactivespecies that can cause a wide spectrum of cell damage including enzyme inactivation, lipid peroxidation, protein andlipoprotein oxidation, and DNA damage. Free radicals are believed to be involved in the pathogenesis ofcardiovascular diseases and cancer. The purpose of the present study was to measure the total antioxidant status(TAS) in active cigarette smoking individuals in Mosul city. Twenty active smokers and twenty nonsmokersparticipated1in the study. Blood sample was taken from each individual and the TAS had been measured in the serausing the Cayman chemical antioxidant assay kit (USA). The results obtained from the study revealed a significant(P<0.001) reduction of the TAS in the smoker’s group as compared with the non-smoker’s group. In conclusion,smokers possess low TAS than non smokers which may be due to the presence of high amounts of free radicals incigarette smoke that generate an oxidative stress in the smoker’s body that may cause exhaustion of antioxidants ofthe body.