Chronic hepatitis C (CHC) should be considered not only as viral but also as a metabolic disease. Insulin resistance (IR), impaired glucose tolerance, type 2 diabetes mellitus, hepatic steatosis, lipid metabolism abnormalities and probably atherosclerosis are the main metabolic manifestations of CHC. The development of IR in CHC seems to be complex, resulting from an ongoing inflammatory process, up-regulation of pro-inflammatory cytokines, fibrosis progression and direct influence of the virus on the insulin signalling pathway. Insulin resistance promotes hepatic steatosis and is associated with fibrosis progression, resistance to antiviral therapy and development of hepatocellular carcinoma. Therefore, understanding the pathogenesis of this phenomenon may by essential to obtain higher efficacy of antiviral therapy and would be helpful in prevention of metabolic disturbances and complications in the course of CHC.