Objectives: The primary role of g-glutamyltransferase is to metabolize reduced glutathione by assimilating and utilizing precursor amino acids for intracellular glutathione synthesis.The aim of this study is to investigate the exact role of g- glutamyltransferase enzyme in the oxidative stress associated with menopause.Methods: This study was carried out at the Chemistry and Biochemistry department, Al-Nahrain University from October 2009 to January 2010. The study participants were categorized into two groups; premenopausal group (n=17) and postmenopausal group (n=16). Blood specimens were collected from each participant by vein puncture procedure. The g-glutamyltransferase enzyme was measured by kinetic spectrophotometric method while glutathione and malondialdehyde were measured by spectrophotometric methods.Results: Serum glutathione levels in pre- and postmenopausal women were 0.62±0.17 and 0.47±0.11 mmol/L respectively. Serum g-glutamyltransferase levels increased significantly in the postmenopausal women group (p=0.025) compared to the premenopausal women group. Serum malondialdehyde levels were 1.04±0.06 and 1.32±0.05 µmol/L in pre- and postmenopausal groups respectively.Conclusion: Serum g-glutamyltransferase may be considered as an index of oxidative stress associated with menopause.