99 patients with ascites (60 patients with liver cirrhosis and 39 patients with peritoneal carcinosis) were examined by ultrasound tomography of the gall bladder. In most of the cirrhotic patients a thick gall bladder wall was found (7.7 +/- 3.4 mm) often with a three-layer structure. The gall bladder wall of the patients with peritoneal carcinosis was most often not thickened (2.5 +/- 1.6 mm). The difference is statistically significant (p less than 0.1). Thickening of the gall bladder wall was found in both groups of patients by a decreased serum albumin level. The ultrasound tomography of the gall bladder could help in the differentiation of cirrhotic from malignant ascites, especially in combination with determination of the serum albumin level.