In the past recent years there have been several major innovations in the diagnosis and evaluation of portal hypertension. These include the application of new endoscopic, ultrasonographic and haemodynamic techniques that allow a better evaluation of the portal hypertensive patient, specially when prophylactic medical therapy is considered. Ultrasonography is very useful to assess the patency of the portal vein. The association of a pulsed Doppler flowmeter increases its accuracy and allows the non-invasive estimation of the direction and magnitude of portal blood flow. Endoscopic measurements of variceal pressure may help to understand the mechanism of variceal bleeding, and perhaps might permit to assess the risk of haemorrhage in the individual patient. In addition to the measurement of portal pressure, measurement of blood flow through the azygos vein has been the major innovation in the haemodynamic evaluation of portal hypertension. Azygos blood flow represents an index of blood flow through gastroesophageal collaterals and varices draining in the azygos vein. This technique has been very useful in the development of new forms of pharmacological therapy for portal hypertension.