The imbalance in to oxidants and antioxidants leads to the condition called oxidative stress. The oxidative stress is considered as one of the etiopathological factors for development and /or exacerbation of psoriasis. Therefore we undertook this study to determine serum levels of oxidants (Malondialdehyde MDA, Nitric oxide NO) and antioxidants (Total Antioxidant Status TAS, Superoxide Dismutase SOD) and it’s correlation with severity of psoriasis. In present research work we have studied 90 clinically diagnosed psoriasis patients and 90 age and sex matched healthy control subjects. Our results showed increased concentration of oxidants; MDA, NO, and decreased concentration of TAS as well as activity of SOD in the serum of psoriasis patients. Observations of our study clearly indicate positive correlation of increasing serum oxidants and negative correlation of decreasing serum antioxidants with PASI scour i.e. severity of psoriasis.