Insulin resistance is frequently associated with chronic liver disease, and the interaction between hepatitis C virus (HCV) infection and insulin resistance is a major public health issue, bound to increase in the near term. Because of their potential synergism on liver disease severity, a better understanding of the clinical consequences of the relationship between HCV infection and insulin resistance is needed. This translates into accelerated liver disease progression, reduced response to anti-viral agents and, in susceptible individuals, increased risk of developing type 2 diabetes. HCV may also cause hepatic steatosis, especially in patients infected with genotype 3, although the clinical impact of viral steatosis is debated. Little is known regarding the effect of anti-diabetic agents on HCV infection, and a possible association between use of exogenous insulin or a sulfonylurea agents and the development of hepatocellular carcinoma has recently been reported. Thus, modified lifestyle and pharmacological modalities are urgently warranted in chronic hepatitis C with metabolic alterations. (Korean J Gastroenterol 2012;59:268-274)