BACKGROUND/AIMS: The clinical significance of serum CA 125 levels in patients with chronic liver disease has not been widely appreciated in relation to the severity of the disease. We examined serum CA 125 levels in patients with chronic liver disease according to the severity of liver disease and the presence of ascites. METHODS: Fasting serum CA 125 levels were measured by a commercial RIA kit in 92 patients with chronic liver disease: 22 with chronic hepatitis and 70 with liver cirrhosis (Child class A, 19; B, 28; C, 23). Forty-one patients (45%) had ascites. RESULTS: The patients with Child class C liver cirrhosis had significantly higher mean serum CA 125 level than those with class A (p<0.05). In Child class B patients, the mean serum CA 125 level was significantly higher in patients with ascites than in those without (p<0.05). A multiple regression analysis showed that the presence of ascites, serum albumin, and prothrombin time were independent factors related to the increase of serum CA 125 levels. CONCLUSIONS: The presence of ascites is more closely related to the increase of CA125 levels in patients with liver cirrhosis than the severity of liver disease.