The aim of our study was to compare levels of antioxidative agent -total SH groups and the final product of lipid peroxidation- malondialdehyde (MDA) in serum, and glutathione (GSH) and MDA in nucleocortical parts of lens after extracapsular extraction of cataract. Patient were (38 with cataract and 38 controls) matched by sex and years of life. Diagnosis of cataract was established by complete ocular examination. All results are expressed as mean ± S.D. A Student's t-test was used to estimate differences between the groups. The level of significance was p<0.05. Total sulfhydryl groups were determined in serum by the method of Ellman as well as GSH content in nucleocortical parts of lenses using the method of Sedlak and Lindsay. Lipid peroxidation, evidenced by formation of thiobarbituric acid reactive substances (TBARS), was determined in nucleocortical parts of the lens and in serum. Our results show a statistical significance in concentration of total SH groups (225.37±82.19µmol/L, controls 311.03±60.37µmol/L p<0.05) and MDA (20.24±8.12, and controls 8.73±2.53µmol/L, p<0,001) in serum among patients with age related cataract and controls. There was no statistical significance in concentration of total SH groups and MDA in serum among patients with different type of age related cataract and in nucleocortical parts of lens. The present study concludes that there is a statistical significance in concentration of total SH groups and MDA in serum among patients with age related cataract and controls, but there were no statistical significance in concentration of GSH and MDA in serum and nucleocortical parts of lens in patient with different type of cataract.