ABSTRACT: BACKGROUND: It has long been recognized that exposure to various metals is highly toxic, producing a wide variety of illnesses, including cancer. The role of these metals in free radical formation and initiation of lipid peroxidation was extensively studied; where the free form of iron or copper can effectively be involved in a free radical generation. OBJECTIVES: To evaluate the effects of the some environmental conditions on the levels of the oxidative stress markers, malondialdehyde (MDA) and glutathione (GSH), and some of the transition metals, iron, copper and zinc, in he serum of Iraqi subjects who exposed to different environmental conditions. METHODS: Blood samples were taken from 137 healthy male adults who work in different types of jobs (25 farmers, 25 workers in gasoline, 25 workers in liquid propane gas, 25 workers in casting, 25 workers in paints and 12 workers in plastic and rubber materials). The serum levels of MDA, GSH, iron copper and zinc were estimated and compared in different groups. RESULTS: The result showed that exposure of healthy subjects to different occupational hazards produces significantly different changes in the oxidative stress markers as revealed by excessive production of the lipid peroxidation end product (MDA) and depletion of the soluble antioxidant (GSH); and impairment of the trace element status (copper and zinc). CONCLUSION: The extracellular defense mechanisms were severely affected by the insults of oxidative stress processes due to environmental pollution in some work places in Iraq.