Abstract: Superoxide dismutase and catalase activities were measured in tissue extracts obtained from cancerous and corresponding non-cancerous tissues of patients with renal adenocarcinoma. The activities of cytosol superoxide dismutase (CuZnSOD) and mitochondrial superoxide dismutase (MnSOD) were decreased significantly (P≤0.02) in cancerous tissues in comparison to non-cancerous tissues, while the activity of catalase (CAT) was increased significantly (P<0.02) in cancerous tissue at stage III-IV. These results suggest that human kidney cancer progression is accompanied by altered antioxidant status of both superoxide dismutase (SOD) and catalase activities.