Liver stiffness, measured by transient elastography (FibroScan), reflects not only fibrosis of the liver but also intrahepatic inflammation and portal hypertension. The diagnostic performance of FibroScan depends on the care and quality of the procedures used to measure liver stiffness. An experienced physician must interpret the liver stiffness measurement as a function of the clinical situation and other imaging and test results. Liver stiffness is strongly correlated with fibrosis of the liver during hepatitis, with co-infection by HCV (hepatitis C virus) and HIV (human immunodeficiency virus), with recurrence of HCV infection after liver transplantation, and with chronic cholestatic diseases. Liver stiffness is strongly correlated with the severity of portal hypertension and of cirrhosis.