We describe a case of spontaneous bacterial peritonitis in a 53 year old man affected by cryptogenic micro-macronodular cirrhosis, portal hypertention, splenomegaly and hypersplenism, who was admitted with hepatic failure and septic shock and successfully treated with antibiotics (combination of clindamycin and netilmycin), surgical abdominal drainage and splenectomy. This case gave reason for a literature review and an update on the therapeutic options in these high risk patients, especially concerning the role of surgery. Spontaneous Bacterial Peritonitis (SBP) is defined as a bacterial infection of ascitic fluid in the absence of any septic focus. It is a typical life-threatening complication of hepatic cirrhosis with ascites. Mortality is very high and ranges from 75% to 97% of patients, due to septic shock and hepatic failure (hepatorenal syndrome, hepatic encephalopathy, gastrointestinal bleeding). Infection with a single organism is found in most cases. Gram negative bacilli are present in about 70% of cases and E. coli (less frequently Klebsiella, Serratia, Pseudomonas) is principally found. Gram positive cocchi comprise an additional 30% of cases. Anaerobic and microaerophilic organisms seem to be rare causes of SBP (2.7-6%); this finding is probably due to the intrinsic bacteriostatic activity of ascites, which contains high oxygen tension (70 mmHg) and is an inhospitable environment for bacteroides and Clostridia. The prevalent isolation of enteric organism suggest that the gut is the most frequent source of infection, even if the pathogenetic mechanism is not yet well known. The right treatment depends on differentiating primary (SBP) from secondary peritonitis.(ABSTRACT TRUNCATED AT 250 WORDS)