 Asthma is a common respiratory disease of unknown etiology which currently affects approximately 7.5 of the adult population . Asthma is an inflammatory disorder of the airways. Airway inflammation is evident not only in patients with fatal asthma but also in mild asthmatics . Oxidant stress, defined as inadequately controlled generation of toxic reactive oxygen species ROS in the cells or tissues is a common feature of inflammation, and has also been documented in asthma , . However, the current understanding of the relationship between the inflammation and the oxidant stress in asthmatic airways is poor. Does oxidant stress contribute to the expression of asthmatic phenotypes independently of inflammation? If so, could asthmatics benefit from supplementation of antioxidants? These questions have been nagging us since our laboratory provided credible evidence of oxidant injury in the airways of allergic asthmatics . The purpose of our study is to more precisely determine 1 the pathophysiologic role of oxidative stress, and 2 usefulness of antioxidant therapy using vitamin E in allergic asthma. 