The present study was carried out in the patients diagnosed with the colorectal cancer andis about to get the treatment. Age and gender matched controls were also included in the study.The blood samples were collected and the biochemical parameters like Total antioxidantactivity, lipid peroxidation, Glutathione, Vitamin E, Vitamin C and catalase were estimated. Thesignificant decreased levels of total antioxidant activity, increased lipid peroxidation levels,decreased levels of glutathione, catalase, vitamin E and vitamin C were observed in the colorectalcancer subjects when compared with the control subjects. It is evident from the present study thatoxidative stress plays an important role in the advancement of colorectal cancer and might bean additional parameter in the pathology of cancer progression.