Abstract To clarify the pathogenesis of ascites in patients with liver cirrhosis, we explored the effects of transjugular intrahepatic portosystemic shunting in six cirrhotic patients with refractory ascites. The portal pressure decreased from 39 ± 7 cmH 2O before treatment to 32 ± 5 cmH 2O immediately after the procedure. Liver function transiently deteriorated after the procedure, but recovered within 1 week. Urinary Na excretion increased 1 week after treatment. In five patients, ascites improved within 3 weeks. Along with the decrease of portal congestion, there was an improvement of esophageal varices, and an increase of gastric mucosal blood flow, and an inhibition of the renin-angiotensin-aldosterone system in all of the patients after 2–4 weeks. Manageable shunt encephalopathy occurred in three patients. These findings strongly suggest the pivotal role of increased portal pressure in the formation of ascites in patients with liver cirrhosis.