Introduction: Welding is the most common way of permanently joining metal parts. Several metals commonly present in welding fumes including Cr, Fe, Mn, Cd and Pb which are capable of generating reactive oxygen species (ROS) resulting in oxidative stress which in turn leading to disease development. Aim of work: The main objective of this work was to detect the health effect of some metals present in welding fumes. Materials and Methods: A case-control study was carried out on two groups, an exposed group and a control group after taking consent from them. The exposed group consisted of fifty workers occupationally exposed to welding fumes of one of the private factories for Iron and Steel industry at El Asher Men Ramadan, their mean age was 20 to 55 years (34.3 ± 6.9) work shift was for 12 hrs/ 6days/ week. The control group included thirty male person were selected from the industrial medicine outpatient clinic in Kasr Al Aini hospital, who were never exposed to welding fumes matching for age 25 to 50 years(34.5 ± 5.8 ), sex, socioeconomic status and smoking habits. All individuals in both groups were examined after taking consent and interviewed using detailed questionnaire including present, past, family history and occupational history. Clinical examination was performed with special emphasis on chest examination. Ventilatory function tests (FVC, FEV1, FEV1/FVC and PEF) were done. Laboratory investigations were performed : determination of blood levels of the following metals (manganese, iron, lead, chromium and cadmium) and determination of serum level of Superoxide dismutase enzyme (SOD). Results: The prevalence of respiratory tract disorders were significantly higher among the welders (20%)compared to the control group(0%) and statistically significant reduction in values of ventilator y function parameters among the exposed workers compared to control group .The levels  of metals showed statistically significant increase among the exposed group more than the control group and statistically significant decrease of superoxide dismutase enzyme level among the exposed group compared to the control group. Conclusion: the level of superoxide dismutase enzyme (SOD) can be a useful biomarker for oxidative status after exposure to welding.