Insulin resistance (reduced insulin action to stimulate glycogen synthesis in muscle and occasionally to inhibit glucose output in liver) is well known to be frequently present in patients with chronic liver diseases, especially cirrhosis. It has been documented that 60% to 80% of patients with cirrhosis are glucose-intolerant, and 10% to 30% eventually develop overt diabetes mellitus when their impaired insulin secretion cannot meet the increased demand for insulin due to insulin resistance. Therefore, it seems rational to treat cirrhotic patients with such an insulin sensitizer as thiazolidinediones. However, it must be forbidden to use thiazolidinediones in cirrhotic patients whose liver function capacity is limited until the possible liver toxicity is clarified.