Health professionals exposed to anesthetic gases are at higher risk of reproductive, neurological, hematological, immunological, hepatic and renal system diseases. We investigated if oxidative stress induced by chronic exposure to anesthetic gases has any association with this matter. Plasma lipid peroxidation, total antioxidant capacity and total thiol molecule levels were measured in 66 operating room staff in comparison with 66 controls. The exposed group had a significantly higher level of lipid peroxidation with decreased thiol groups compared to control subjects. Total antioxidant capacity of the body was no different among exposed and not exposed subjects. Increased lipid peroxidation in the blood of exposed subjects warns that oxygen free radicals have increased in the body and thus might attack cells, which, in the long-term, results in multi-organ damage. The remaining blood total antioxidant capacity at normal values is promising and means that other non-thiol antioxidants, such as uric acid, transferrin, ceruloplasmin, albumin, and vitamin antioxidants, such as alpha-tocopherol and ascorbic acid, have been stimulated to maintain the total anti-oxidant power of the body at normal state.