NAFLD (non-alcoholic fatty liver disease) is the most frequent chronic liver disease and is frequently associated with diabetes. Its pathogenesis is complex and consists in hepatocyte fat accumulation, inflammation and mitochondrial dysfunction. Its diagnosis is based on imaging and blood tests to exclude other causes of liver disease. Liver biopsy remains the gold-standard in case of doubt. Medications have relatively little efficacy and the main measures to treat NAFLD are weight loss and exercise. Although controversies exist, NALFD is now considered as a cardiovascular risk factor in diabetes and it is therefore important to treat all cardiovascular risk factors.