MircoRNA's (miR) have been recognised as important modulators of gene expression and potential biomarkers. However, they have been rarely investigated in bio fluids apart from blood. We investigated the association of miR-125b and miR-155 with complications of cirrhosis. Ascites was prospectively collected from patients with cirrhosis undergoing paracentesis at our department. miR's were determined in the supernatant using qPCR and normalized by SV-40. Clinical parameters were assessed at paracentesis and during follow-up. 76 specimens from 72 patients were analysed. MiR's were not associated to age, sex or aetiology of cirrhosis. MiR-125b levels differed between patients with low and high MELD score, and miR-125b levels showed an inverse correlation to serum creatinine (r2 = -0.23; p = 0.05). MiR-155 was elevated in patients with spontaneous bacterial peritonitis (SBP) (n = 10; p = 0.04). MiR-155 levels differed between patients with and without 30-day survival (p = 0.02). No association of ascites levels of investigated miR's to size of varices, episodes of gastrointestinal bleeding or hepatorenal syndrome was observed. While miR-125b levels in ascites seem to be associated with liver and renal dysfunction, miR-155 might be implicated in local immune response in SBP.