The soluble hexavalent chromium Cr (VI) used in industrial welding is an environmental contaminant widely recognized to act as a carcinogen, mutagen and teratogen towards humans and animals. The carcinogenic potential of metals is a major issue in defining human health risk from exposure. In the present investigation, 93 welders and 60 control subjects with similar mean ages, smoking prevalences and alcohol consumption were enrolled for DNA damage analysis in blood leucocytes by Micronucleus assay (MN) and the Comet assay. DNA repair inhibition was also analyzed by assessing XPD gene polymorphism. Welders showed a significant increase in micronucleated cells compared to controls with respect to their smoking habits and alcohol consumption, age and years of exposure (P<0.05). Results indicated that the welders had a larger mean comet tail length than that of the controls (P<0.05). The current study suggested that chronic occupational exposure to Cr (VI) during welding could lead to increased levels of DNA damage and repair inhibition.