The prevalence and natural history of spontaneous bacterial peritonitis in asymptomatic patients with ascites secondary to cirrhosis is unknown. From a prospectively recorded database, we reviewed the clinical and laboratory features of all outpatients with cirrhotic ascites undergoing paracentesis between July 1994 and December 2000. The prevalence of spontaneous bacterial peritonitis in the population of 427 cirrhotic outpatients as defined by neutrocytic ascites (absolute neutrophil count >250 cells/mm 3 ) was 3.5%. Of the 15 patients with neutrocytic ascites, 6 were culture positive (1.4%) and 9 culture negative (2.1%). Eight other patients (1.9%) had bacterascites. The organisms cultured from ascitic fluid in these asymptomatic patients with culture positive neutrocytic ascites and bacterascites were predominantly gram positive. No patient developed hepatorenal syndrome, and 1-year survival of 67% was better than historical data from hospitalized patients with spontaneous bacterial peritonitis. Moreover, patients who did not receive antibiotics for neutrocytic ascites fared no worse than patients who did receive antibiotics. In conclusion, spontaneous bacterial peritonitis in outpatients with cirrhotic ascites is less frequent, occurs in patients with less advanced liver disease, and may have a better outcome than its counterpart in hospitalized patients. S pontaneous bacterial peritonitis (SBP) is a potentially life-threatening complication in patients with cirrhosis and has typically been described in hospitalized patients. In this group, SBP may be complicated by renal failure, systemic sepsis, recurrence, and diminished survival. 1-3 The prevalence of SBP in hospitalized patients with cirrhosis and ascites is between 10% and 30%. [4][5][6] The prevalence and outcome of SBP in asymptomatic outpatients with cirrhotic ascites has been less well studied. A small study of 29 patients with ascites undergoing repeated large volume paracentesis for refractory ascites did not demonstrate any patients with SBP. 7 In 1998, the American Association for the Study of Liver Disease (AASLD) published guidelines for the initial ascitic fluid analysis in outpatients with cirrhosis. 8 The guidelines recommend determination of total nucleated cell count and a differential cell count on the initial ascitic fluid sample. Routine ascitic fluid bacterial cultures are not recommended unless infection is suspected. The AASLD guidelines recommend that a second paracentesis be carried out to obtain ascitic fluid for bacterial culture and antibiotic susceptibilities if the initial paracentesis shows an absolute neutrophil count of Ն250 cells/mm 3 (neutrocytic ascites). This recommendation, however, is based on data from a small Spanish study of 51 patients published only in abstract form. 9 The International Ascites Club recommends that routine cultures be obtained on ascitic fluid in hospitalized patients; the issue of ascitic fluid cultures in outpatients undergoing paracentesis is not addressed. 10 Thus, it appears that the majo...