Background and study aim: Renal dysfunction often develops in patients with liver cirrhosis. Hepatorenal syndrome (HRS) represents the end-stage of reduction in renal perfusion. Duplex Doppler ultrasonography of the kidneys is a non-invasive method to assess blood flow and arterial vascular resistance as a parameter for vasoconstriction. This study aimed to assess the role of renal resistive index as a non-invasive marker for early detection of functional renal impairment in patients with liver cirrhosis. Patients and Methods: This study was conducted on 20 patients with liver cirrhosis without ascites vs. Session [CurrentTestPartID] patients with liver cirrhosis and ascites and 20 healthy subjects as control group. Patients and control were subjected to complete blood picture, liver and kidney functions, serum electrolytes, twenty four hours urinary sodium, abdominal ultrasonography and duplex Doppler evaluation of the renal arteries with calculation of mean renal RI. Results: Highly significant difference between cirrhotic patients with ascites and cirrhotic patients without ascites and controls regarding mean renal resistive index for both kidneys (P<0.001). At Cutoff point of renal RI 0.71, the sensitivity, specificity and accuracy to predict HRS were 100%, 80% and 82% respectively with AUC= 0.997. A statistical high significant positive correlation between RI and serum creatinine, child class, MELD score and MELD-Na (r=0. 0.818, r= 0. 0.539, r= 0.739 r= 0.807 respectively and P<0.001). A statistical high significant negative correlation between RI and serum sodium, Session [UserIDID] hours urinary sodium, and platelets (r= -0.778, r= 0. -0.688, r= -0.422 respectively and P<0.001). Conclusion: Renal duplex Doppler ultrasound is useful as a non-invasive method for the evaluation of the renal hemodynamic changes in cirrhotic patients and can predict HRS.