Several methods have been used for diagnosing insulin resistance in humans. Glycemic clamp continues to be the gold standard procedure; however, its complexity limits its application in daily medical practice. Several methods using glycemia and insulinemia measurements, both during fasting or after oral or endovenous glucose overload, have been proposed. The purpose of this study was to identify the fasting insulin level and insulin resistance detected by HOMA-IR test in ICU patients as predictors for hepatic encephalopathy. This was a case-control study. The study was done in the medical intensive care unit (ICU) of the Faculty of Medicine Cairo University, 319 ICU patients were included in the study. Control subjects without acute illness were recruited from the local community, stratified by age and gender to approximate the sepsis cohort. In our study we found that hepatic encephalopathy is associated with statistically significant less fasting insulin levels and less insulin resistance than patients without hepatic encephalopathy. This may be explained by that end stage liver disease is associated with hypoglycaemia due to defective hepatogluconeogenesis which causes reduction in calculation of HOMA test. Our present observations indicate that patients with hepatic encephalopathy are associated with statistically significant less fasting insulin levels and less insulin resistance than patients without hepatic encephalopathy.