Abstract: Hepatic encephalopathy one of the most serious complications of liver diseases which is responsible for the major cause of admission and high mortality in cirrhotic patients.  So effective educational nursing intervention may be of great value in minimizing hepatic encephalopathy episode. Purpose: was to examine the effect of educational nursing program on hepatic encephalopathy severity among patients with liver cirrhosis. Design: a quasi-experimental research design was utilized. Setting: The current study was carried out at endemic diseases department and the outpatient clinics of Menoufia University Hospital as well as National Liver Institute at Shebin El-Kom, Menoufia Governorate, Egypt. Subjects: A consecutive sample of 100 adult patients with liver cirrhosis were assigned randomly and alternatively into two equal groups, 50 patients for each group. Instruments: Three instruments were used for data collection: Structure interview questionnaire, bio - physiological measurement instrument and West-Haven criteria scale (WHC scale). Results: It is revealed that 92% and 96% of study and control groups respectively had poor total knowledge pre- intervention. While 90% and 86% respectively of study group compared to 0.0% of control group had good total knowledge level immediately post intervention and after 2 months. There was highly statistically significant reductions in hepatic encephalopathy severity grade among study group compared to control group immediately post intervention and after 2 months, in which majority of study group (88%) didn't have hepatic encephalopathy abnormality compared to 48% of control group after 2 months of educational nursing intervention. Conclusions: Educational nursing program had a positive impact on reducing hepatic encephalopathy episodes and its severity among study group (group I) than control group (group II). Recommendations: Supervised health teaching should be given for all patients with liver cirrhosis to improve their knowledge and awareness about hepatic encephalopathy, its prevention and early detection especially for high risk persons. Also establishing a web site, including all information pertained to hepatic encephalopathy and all aspect of health education such as different educational materials, medias and audio-visual aids.