Abstract Many welders have experienced bronchitis, metal fume fever, lung function changes, and an increase in the incidence of lung infection. The aim of the present study is to clarify the effect of welding fumes as pulmonary oxidative stress on allergic factors, antioxidants, some minerals and immunoglobulines of smoking and non-smoking iron and steel workers. In order to achieve this aim 40 male iron and steel workers of whom 20 were smokers and 20 non-smokers, were recruited. Control subject were 20 healthy volunteer never exposed to welding fumes and non-smoking. The result of the present study showed a significant association between exposure to welding fumes and high level of iron, copper, lead, and manganese, low zinc level, high catalase activity, low super oxide dismutase activity, low glutathione reductase and peroxidase activity, low reduced glutathione level, high level of malondialdhyde, low nitric oxide level, high cortisol level and high immunoglobulines level. These parameters may all be regards as risk factors for exposure to welding fumes. The finding of the present study suggest that oxidative stress, vascular inflammation, allergic reactions and recurrent infections are primary interacting mediators of diseases caused by exposure to welding fumes.