Background: Renal failure is a challenging complication of liver cirrhosis. Patients with cirrhosis and renal failure are at high risk for death while awaiting transplantation. They also have an increased frequency of complications and reduced survival after transplantation. Aim: to evaluate the predictors of renal failure in patients with decompensated liver cirrhosis. Patients and Methods:The study included 86 patients with decompensated liver cirrhosis in Suez Canal University Hospital. Data were collected using a questionnaire that included personal data , full medical history, clinical examinations, Laboratory investigations included prothrombin time (PT), complete blood count (CBC), serum creatinine, urea and uric acid, complete urine analysis, random blood glucose, alanine transaminase (ALT), aspartate transaminase (AST), serum direct and indirect bilirubin, serum albumin, total protein, and alkaline phosphatase, serum and urinary sodium, chemical and cytological assessment of ascetic fluid And at last pelvi-abdominal ultrasound and outcome measures [Child-Pugh and Model for End-stage Liver Disease (MELD) scores]. Results: There were statistically significant higher mean age, higher mean duration of hospital stay and higher mean MELD score in the studied patients with renal failure than the patients without renal failure (p=0.001). Also, there were higher frequencies of smoker patients, patients with SBP, and patients with variceal bleeding in the studied patients with renal failure than in the patients without renal failure (p=0.01). Significant predictors include age >55years (odds ratio (OR)=3.5), SBP (OR=4.8), variceal bleeding (OR=14.7), urine sodium (OR=11.8), serum sodium (OR=7.9), and MELD score>25 (OR=15.6). Conclusions: Low urinary and serum sodium, high bilirubin and MELD score are significant predictors of renal failure in patients with decompensated liver cirrhosis.