Patients with liver cirrhosis present an increased incidence of infections. The main cause has been founded in alterations of the enteric flora and of the intestinal barrier probably due to portal hypertension, in addition to a reticulo-endothelial system dysfunction. Furthermore, those living with cirrhosis can report a high predisposition to sepsis and septic shock, due to the excessive response of pro-inflammatory cytokines and a complessive hemodynamic derangement. By the analysis in the experimental model of the cirrhotic rat, it was demonstrated that radio-labelled Escherichia coli given by the oral route resulted in the location of the bacteria in the gut, the ascitic fluid and mesenteric lymph nodes, a phenomenon known as bacterial translocation. Bacteria encountered with the highest frequency are those colonizing the intestinal tract, such as E. coli, Klebsiella pneumoniae and Enterobacteriaceae, intracellular bacteria and parasites are reported with a lower frequency. Multi-drug resistant bacteria are cultured with the highest frequency in those with frequent hospitalisations and report both high septic shock and mortality rates. Spontaneous bacterial peritonitis (SBP) is the commonest infection in cirrhotic, estimated to occur in 10-30% of the cases with ascites. A practical approach may include administration of a protected penicillin, III generation cephalosporin or quinolones in uncomplicated cases. Instead, in complicated cases and in nosocomial SBP, administration of cephalosporin or quinolones can be burned by the high resistance rate and drugs active against ESBL-producing bacteria and multi-drug resistant Gram positive bacteria have to be considered as empiric therapy, until cultures are available. When cultures are not readily available and patients fail to improve a repeated diagnostic paracentesis should be performed. Current investigations suggest that norfloxacin 400 mg/day orally has been reported to successfully prevent SBP in patients with low-protein ascites and patients with prior SBP.