Introduction: The Pediatric Risk of Mortality (PRISM) score is a physiology basedscoring system used to quantify risk of mortality in pediatric intensive care unit(PICU) populations.The aim of this study: was to evaluate the use of the PRISM score to predict theoutcome of patients with end stage liver disease (ESLD) and fulminant hepaticfailure (FHF).Patients and methods: This present study included 30 patients with ESLD andFHF, whose ages ranged from 2 to 108 months, who were admitted to the Emergencyroom (ER) and the Hepatology department of Cairo University Pediatric Hospital(tertiary referral hospital) during the period from May to November 2008. Survivingpatients were followed up for 6 months till May 2009.Results: Deceased patients compared with survivors were significantly younger(median age 7 vs 24 months). The median PRISM Score was 10. Deceased patientsshowed higher PRISM Score than survivors (15 vs 9). The GCS (p = 0.002) and thesystolic blood pressure (p = 0.001) showed high statistical difference betweensurvivors and deceased patients. The diastolic blood pressure (p = 0.015), respiratoryrate (p = 0.033), PCO2 (p = 0.018) and the pupillary response (p = 0.052) werestatistically different between them. Other laboratory tests including tests of liverfunction such as serum bilirubin (p = 1.00), PT and PTT (p = 0.961) did not show anystatistical significance.The PRISM score was not significantly different within the different ESLD and FHFetiologies (p = 0.385). Neither the PELD score (p = 0.2), nor the Child-Pugh score ( p= 0.4) was associated with mortalityConclusion: The PRISM score is a good means of severity assessment & mortalityprediction in pediatric ESLD and FHF patients, with a cut-off point of 9.5, 70.6%sensitivity and 61% specificity. A death probability higher than 5.95 had a 70.6% sensitivity and 85% specificity.