The current study was designed to investigate the changes of oxidative stress (OS) in primary infertility of females. To achieve the intended aim, 84 infertile women of ages 28.66 ± 6.29 years (mean ± SD) and 30 healthy fertile women of ages 30.3± 6.45 years (mean±SD) were enrolled. The levels of malondialdehyde (MDA), catalase (CAT) and glutathione-S-transferase (GST) were determined by spectrophotometric methods. Serum follicule stimulating hormone (FSH) and luteinizing hormone (LH) levels were measured by an enzyme linked fluorescent assay (ELFA). The results indicated a significant (p<0.001) increase of MDA concentration and significant (p<0.001) decreases of CAT and GST activities in the infertile women when compared with those of the control group. The linear regression analysis demonstrated significant (r = 0.27,p<0.05) positive correlation for MDA levels and significant negative correlations for CAT (r = - 0.24, p<0.05) and GST levels (r = - 0.26,p<0.05) with the age of infertile women. Changes of oxidative stress was observed to be dependent on the body mass index (BMI) and the duration of infertility of the enrolled women. The changes of MDA, CAT and GST levels seem to be independent on etiology of infertility and the menstruation pattern. The2linear regression analysis revealed significant (r = 0.28, p<0.05) positive correlation for MDA levels with the FSH concentration and significant(r = - 0.29, p<0.05) negative correlation with the LH concentration.CAT exhibited significant (r = 0.30, p<0.05) positive correlation with the FSH concentration, while GST activity demonstrated significant(r = 0.24, p<0.05) positive correlation with the LH concentration. These results suggest that oxidative stress is involved in the path ophysiology of primary infertility in females, in particular through the directing of gonadotrophin changes in these patients.