The aim of this study was to evaluate differences in gallbladder contractility by measuring gallbladder wall thickness, fasting and residual gallbladder volume, and gallbladder ejection fraction in patients with cirrhotic and malignant ascites. Twenty-four patients (16 women and 8 men) with malignant ascites (2 cervical, 2 colon, 2 stomach, 6 pancreatic, and 12 ovarian carcinomas), aged 59 +/- 12 years, and 26 patients (14 women and 12 men) with cirrhotic ascites, aged 57 +/- 16 years, were included in the study. After patients fasted overnight for 8 hours, gallbladder wall thickness, fasting gallbladder volume, and gallbladder volume and ejection fraction were measured sonographically at 10, 20, 30, 40, 50, 60, 70, 80, and 90 minutes after ingestion of a standard liquid test meal. The mean gallbladder wall thickness was higher in patients with cirrhotic ascites than in those with malignant ascites (5.5 +/- 1.5 mm [standard deviation] versus 3.1 +/- 0.6 mm, respectively; p < 0.001). The mean fasting gallbladder volume was also higher in patients with cirrhotic ascites than in those with malignant ascites (27.3 +/- 11.5 cm(3) versus 17.6 +/- 8.9 cm(3); p < 0.05). Patients with cirrhotic ascites had significantly higher mean postprandial gallbladder volumes and ejection fractions than did those with malignant ascites at all times except 10 minutes after the meal (p < 0.05). Our findings suggest that gallbladder contractility is greater in patients with cirrhotic ascites than in patients with malignant ascites.