Abstract: The effect of low-protein diet on the activity of antioxidant enzymes (Catalase and Superoxide dismutase) and the status of lipid peroxidation as assessed by malondialdehyde levels in the brain, liver kidney, lungs and heart of rats were studied. Male weanling rats were maintained on low protein diets (2% of protein in diet instead of 25%) for a period of four weeks. Malondialdehyde contents (levels) of tissues of animals fed low - protein diet was significantly increased (P<0.05) when compared with the control. The heart recorded the highest level of malondialdehyde when compared with other tissues. The activities of superoxide dismutase and catalase were significantly increased in the brain and liver of rats fed low protein diet while a significant reduction was observed in the kidney and lungs. It may therefore mean that the ingestion of low- protein diet might led to increased tissue lipid peroxidation (oxidative stress) and altered the activity of antioxidant enzymes.