Oxidative stress and protective antioxidants are the newer aspects of human infertility. This study evaluated the extent of oxidative stress by measuring lipid peroxidation end product, malonaldehyde (MDA) and the role of potent non- enzymatic antioxidant, reduced glu-tathione in the seminal plasma of human subjects with different fertility potential. Semen samples from 48 normozoospermic controls, 34 oligoasthenoteratozoospermics, 34 as-thenoteratozoospermics, and 32 azoospermics were analyzed for physical (sperm concentra-tion, motility, morphology) and chemical (MDA, reduced glutathione) parameters. Signifi-cance of difference among the groups and coefficient of correlation between the parameters was tested statistically. MDA level was found to be significantly higher in the abnormal groups (oligoasthenoterato and asthenoteratozoospermics) than the normozoospermics (p< 0.01). Negative correlation was also found between MDA levels, sperm concentration, sperm motility and sperm morphology. Levels of reduced glutathione were found to be signifi-cantly higher in normozoospermic than the other abnormal groups (p < 0.01). Moreover, it was found to be correlated positively with all seminogram parameters and negatively with MDA level. The study revealed that high lipid peroxidation is associated with diminished fertility potential where as reduced glutathione has a positive correlation with seminogram parameters.