There are large growing data demonstrating that reactive oxygen species are involved in initiation and development of many different neuropsychiatric disorders including schizophrenia. Oxidative stress is a state of disequilibrium between oxidant process and the antioxidant defense system as a consequence of increased production of free radicals or when the antioxidant system is inefficient or a combination of both events. In order to examine lipid peroxidation and antioxidant status in study subjects (40 schizophrenic patients and 40 healthy controls), the levels of malondialdehyde (MDA) as an index of lipid peroxidation and free radical scavenging antioxidants like erythrocyte superoxide dismutase, glutathione, vitamin E, vitamin C and TAC have been evaluated. The objective of this study is to investigate the oxidant/ antioxidant imbalance leading to oxidative stress. Significantly lower levels of the antioxidant were found in patients as compared to normal controls with an increased oxidative stress as indicated by high plasma malondialdehyde levels and nitric oxide metabolites. This study shows that the dysregulation of oxidant and antioxidant defense system might be important mediator for development and progression of clinical conditions in schizophrenia. So, the findings also provide the theoretical basis to develop the new therapeutic approach towards antioxidant supplementation.