BACKGROUND Clinical detection of ascites is a sign of decompensation and correlates with shorter survival in patients with cirrhosis. However, the prognostic relevance of sole detection of ascites by ultrasound (subclinical ascites) is not investigated so far. The aim of the study was to investigate the prognostic relevance of subclinical ascites detected by ultrasound in comparison to absent or clinically detectable ascites in patients with cirrhosis. METHODS Between 11/1995 and 11/2004 a total of 729 patients with cirrhosis underwent sonographic and hemodynamic (including measurement of HVPG) evaluation. The mean follow up time was 47 months (range: 0.13 - 131). Kaplan-Meier survival curves and multivariate analysis were used to investigate differences. RESULTS 443 patients were included in the final investigation - 153 patients without ascites, 38 with subclinical ascites and 252 patients with clinical ascites. Kaplan Meier survival curves were significantly different between the three groups (p < 0.001). Interestingly, patients with subclinical ascites had similar values compared to patients with clinical ascites regarding parameters of portal hypertension (HVPG) and liver dysfunction (INR), while parameters of systemic and renal dysfunction (heart beat, creatinin, serum sodium) were similar to patients without ascites. MELD, Child-Pugh score and ascites were independent predictors of mortality in the entire group, while Child-Pugh score and HVPG were independent factors in the subclinical ascites group. CONCLUSIONS Detection of subclinical ascites by ultrasound allows the identification of a group of cirrhotic patients with intermediary survival compared to patients without or with clinical ascites. This group of patients is characterized by severe portal hypertension but absence of systemic and renal dysfunction.