There is now consistent epidemiological evidence for an association between chronic hepatitis C and diabetes. Important, although so far limited longitudinal data, have documented an increased risk for diabetes in patients infected by hepatitis C virus (HCV) especially in those with metabolic risk factors such as a high BMI and older age. HCV encoded proteins might alter insulin signalling thus explaining impaired insulin sensitivity and the occurrence of glycaemic dysregulation even before the cirrhotic stage. The consequences of the association between diabetes and HCV infection are an increased liver fibrosis stage and faster fibrosis progression rate. This article reviews recent human and experimental data on the HCV-diabetes association.