Chronic hepatitis C (CHC) and diabetes have a complex relationship. CHC increases the risk of developing diabetes, independently from the degree of liver fibrosis. This is due to both impairment in beta cell func¬tion and induction of insulin resistance. Conversely, diabetes worsens the liver-related prognosis of patients with CHC. Sustained virologic response, obtained by either interferon-based or interferon-free regimens, leads to a lower incidence of diabetes, to improved diabetes control in patients with known diabetes and to a lower incidence of micro- and macrovascular diabetic complications.