Background: Non-nutritive sweeteners are commonly used as sugar substitutes to provide sweet taste without calories. However, there is controversy regarding their safety and potential health effects. This study evaluated the effects of commercial non-nutritive sweeteners including sucralose, aspartame, saccharin, acesulfame-K and stevia on oxidant/antioxidant balance in albino rats. Methods: Six groups of rats were administered optimized doses of sweeteners for 8 weeks. Oxidative stress was assessed by measuring malondialdehyde (MDA) and total antioxidant status (TAS) before and after treatment. Results: Aspartame and stevia significantly increased TAS whereas sucralose and acesulfame-K decreased it. All sweeteners except stevia significantly increased MDA levels. Conclusion: The results indicate that long-term intake of commercial non-nutritive sweeteners disrupt redox homeostasis in rats. However, stevia may have relatively less adverse effects. Further research is warranted to fully elucidate the mechanisms and health implications.