Abstract: The aim of the present study was to estimate the effect of age and gender on the levels of primary and secondary antioxidants and Malondialdehyde in red blood cells of the selected Schizophrenia patients. In our present study, the activities of six free radical scavenging enzymes (super oxide dismutase (SOD), catalase (CAT)), glutathione peroxidase (GSH-Px), glutathione Transferase (GST), glucose-6-phosphate dehydrogenase (G6PD), Caeruloplasmin ferroxidase (Cp) and the level of thiobarbituric acid-reactive substances (TBARS) as an index of lipid per oxidation were analyzed in the different age groups of schizophrenia patients. Role of gender was also analyzed in both schizophrenia and control subjects. It was observed from the results that there was a significant increase in erythrocyte MDA levels and activity of SOD and a significant decrease in erythrocyte CAT,GSH- Px, Cp-ferroxidase and G6PD levels in patients with schizophrenia, when compared to controls (p<0.01). The results have also shown that among different age groups, highly significant oxygen free radical production, evidenced by increased levels of MDA and decreased levels of antioxidant enzymes activity was found in adult and elderly schizophrenia patients, which supports the more pronounced oxidative stress in adult and elderly schizophrenia patients when compared to young schizophrenia patients. The statistically more significant increase (p<0.001) in the activity of SOD in elderly schizophrenia subjects may be a compensatory regulation in response to increased oxidative stress in elders. The decreased concentrations of the CAT, GSH-Px, G6PD and Cp-ferroxidase support the hypothesis that lipid per oxidation is an important causative factor in the pathogenesis of schizophrenia. These data reveal that antioxidant defense mechanisms might be impaired a lot in normal elderly people and schizophrenia patients with age group above 30 (i.e., adults and elders). As for as gender concerned, we observed a significant raise in the levels MDA, SOD and significant decrease in the levels of selected antioxidant enzymes in schizophrenia male and female subjects when compared with the respective control male and female subjects (p<0.01). But we found statistically more significant increase in the levels of MDA and highly significant decrease in the levels of the secondary antioxidant enzymes G6PD and Cp ferroxidase (p<0.001) were found in schizophrenia males when compared with schizophrenia females. Supplementation of antioxidants may prevent further oxidative injury in elderly schizophrenia patients.