Background: In cirrhotic liver increased secretion of endotoxin by extrahepatic macrophages may play an important role in the progression of Hepatic encephalopathy (HE). The aim of the present study was to evaluate serum endotoxin in cirrhotic patients with HE and to investigate relation between serum endotoxin level and severity of liver disease and grades of HE. Patient and methods : This study included Four groups: Group I was 25 apparent healthy age and sex matched participants as a control group.  Group II was 25 cirrhotic patients without HE. Group III was 25 cirrhotic patients with minimal HE and Group IV was 25 patients with overt HE. Serum endotoxin was measured in the 4 groups. Results: there was a high statistically significant positive correlation between endotoxin level with WBCs, PT, INR, PTT, RBS, ALT, AST, total, direct bilirubin, urea, creatinine, and HE grades, while there was statistically significant negative correlation with Hb, platelets, serum K, Na level. Total proteins, serum albumin, child pugh score and GCS. Endotoxin level can detect 100% of HE patients and excluding 97.3% of cirrhotic patients with no encephalopathy, with 98% accuracy.  Conclusion: Serum endotoxins is elevated in patients with HE. Serum endotoxin correlate well with grades of HE