To detect differences of the portal hemodynamic response by meal in normal subjects and patients with chronic liver disease, calibers, mean flow velocities and flow volumes of portal vein and splenic vein were measured in 27 normal subjects, 15 patients with chronic active hepatitis (CAH) and 21 patients with liver cirrhosis after an overnight fast and 60 min after the end of a meal (1000 Kcal) using a duplex Doppler ultrasound, which allows a noninvasive assessment of portal hemodynamics. The results obtained are as follows: 1) In the fasting state, the portal vein caliber was significantly higher in liver cirrhosis than in normal control and CAH and the mean flow velocity in the portal vein was significantly lower in this group (p<0.01), whereas the flow volume of the portal vein was not significantly different in liver cirrhosis from the normal control and CAH. 2) At sixty minutes after meal, the calibers, mean flow velocities and flow volumes of the portal vein in normal control and CAH increased significantly (p<0.01), whereas in liver cirrhosis these parameters remained almost unchanged. 3) In the fasting state, the splenic vein caliber was significantly higher in liver cirrhosis than in normal control and CAH and the mean flow velocity in the splenic vein was significantly lower in this group (p<0.01), whereas the flow volume of the splenic vein was pignificantly higher in liver cirrhosis than in the normal control and CAH (p<0.05). 4) At sixty minutes after meal, the splenic vein calibers in normal control and CAH increased significantly but the mean flow velocities decreased significantly (p<0.01) and so, the flow volumes remained unchanged, whereas in liver cirrhosis these parameters remained almost unchanged. These results suggest that a lack of response of portal flow to a meal may represent an indirect sign of the presence of increased intrahepatic resistance, and that the evaluation of hemodynamic response by meal in patie~nts with chronic liver disease using the duplex Doppler system may help to make a diagnosis of portal hypertension.