BACKGROUND Malignant ascites results from imbalance between protein in the peritoneal cavity and absorption of fluids via the lymphatic system. More than 20 interleukins (ILs) are known to play an important role in the protection against tumors. METHODS Ascitic fluid IL-1B, IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ levels were assessed in 45 patients with liver cirrhosis and ascites as judged by histopathological and ultrasonographic findings. They were divided into 2 groups according to presence of hepatic focal lesions. Ten patients with focal hepatic lesions were randomly selected and subjected to analysis of serum levels of IL-2 and IL-10. RESULTS Ascitic fluid IL-4, IL-6 and IL-10 levels were found to be significantly higher in patients with hepatocellular carcinoma (HCC) than patients with cirrhosis. TNF-α, and IFN-γ were also found to be higher in HCC than patients with cirrhosis but with no significance. On the other hand, there was no significant difference in levels of IL-1B and IL-2 between the 2 groups. Ascitic fluid IL-2 and IL-10 levels were found to be higher in ascitic fluid than in serum of the same patients. CONCLUSIONS Ascitic fluid levels of IL-4, IL-6 and IL-10 are higher in HCC patients than patients with cirrhosis alone. Levels of ascitic fluid IL-2 and IL-10 proved to be a better prognostic tool than their levels in sera of the same patients. To conclude, patients with cirrhosis may be subjected to scheduled examination of ascitic fluid cytokines to predict transformation into HCC.