The caliber of the splenic and hepatic arteries, the hepatic to splenic artery ratio and the spleen size (area of widest spleen section) were evaluated by real time ultrasonography (US) in 88 patients affected by liver cirrhosis of different etiology (26 alcoholic cirrhosis, 43 hepatitis B virus (HBV) related cirrhosis, 8 cryptogenic cirrhosis and 11 primary biliary cirrhosis) and in a control group of 21 normal subjects, in order to assess the possible influence of the etiology of the disease on these morphological parameters. The mean caliber of the hepatic artery was larger, and the mean caliber of the splenic artery smaller in alcoholic than in HBV-related, cryptogenic and in primary biliary cirrhosis. This difference is emphasized when considering the hepatic to splenic artery ratio: this parameter was never greater than 0.9 in all cases of primary biliary cirrhosis, in 38 out of 43 patients with HBV-related cirrhosis and in 6 out of 8 cryptogenic cirrhosis, while in the alcoholic group only in one out of 26 was it less than 0.9. The sensitivity, specificity and accuracy of this ratio in differentiating alcoholic from non-alcoholic cirrhosis was 96%, 88% and 91%, respectively. Splenomegaly resulted more in primary biliary cirrhosis, in HBV-related cirrhosis and in cryptogenic cirrhosis than in the alcoholic form. Finally, a significant correlation was found in all groups of cirrhotic patients between the diameter of the splenic artery and the spleen size. These results show that some ultrasonographic morphological features of liver cirrhosis differ according to its varied etiology, probably reflecting different pathophysiological mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)