Clinicians sometimes experience treatment failure in the initial empirical antibiotics treatment using cephalosporins in cirrhotic patients with spontaneous bacterial peritonitis (SBP). Enterococcus, which is intrinsically resistant to cephalosporins, may be one of the causes of treatment failure. The aim of this study was to evaluate the clinical importance and the clinical characteristics of spontaneous enterococcal peritonitis (SEP). This was a retrospective cohort study of 359 patients with SBP treated in a single tertiary care center in South Korea from January 2000 through December 2004. We evaluated the clinical manifestation and the treatment results of SBP patients with enterococci identified from ascites culture. During the observation period, 13 of 359 patients (3.6%) diagnosed with culture-positive SBP had enterococcal peritonitis. For the initial empirical treatment, third-generation cephalosporins were administered to the 13 patients, ten of whom (76.9%) did not improve in the first 48 h. An in vitro antibiotic sensitivity test showed that the identified enterococci were susceptible to ampicillin plus gentamycin in eight patients (61.5%) and there was no vancomycin-resistant enterococcus. Although antibiotics were changed to antienterococcal antibiotics in 11 patients, only five patients improved. As a result, eight of the 13 patients (61.5%) with enterococcal SBP died during the observation period, and the one-month mortality was significantly higher from enterococcal SBP than from nonenterococcal SBP (P = 0.038). We conclude that enterococcal SBP has poor prognosis and it is reasonable to use antienterococcal antibiotics when enterococcus is identified from ascites culture of patients with liver cirrhosis.