Abstract: Down Syndrome (DS) is a common genetic disorder characterized by an extra copy of chromosome 21, leading to dysregulation of various metabolic pathways. Oxidative stress in DS is associated with neurodevelopmental defects, neuronal dysfunction, and the onset of dementia re-sembling Alzheimer's disease. Additionally, chronic oxidative stress contributes to cardiovascular diseases and certain cancers prevalent in DS individuals. This study investigates the impact of ageing on oxidative stress and liver fibrosis using a DS murine model (Ts2Cje mice). The liver in DS mice shows increased oxidative stress and impaired antioxidant defenses, as evidenced by reduced glutathione levels and increased lipid peroxidation. Furthermore, DS liver exhibits an altered in-flammatory response as measured by the expression of cytokines and heat shock proteins. DS liver also displays dysregulated lipid metabolism, indicated by altered expression of peroxisome prolif-erator-activated receptors and fatty acid transport proteins. Consistently, these changes might contribute to non-alcoholic fatty liver disease development, a condition characterized by liver fat accumulation. Finally, histological analysis of DS liver reveals increased fibrosis and steatosis, in-dicative of potential progression to liver cirrhosis. This finding highlights the increased risk of liver pathologies in DS individuals, particularly when combined with the higher prevalence of obesity and metabolic dysfunctions in DS patients. These results shed light on the liver's role in DS-associated pathologies and suggest potential therapeutic strategies targeting oxidative stress and lipid metabolism to prevent or mitigate liver-related complications in DS individuals.