The aim of this retrospective study was to define prognostic factors for cure and survival after spontaneous bacterial peritonitis. In a 4-year period from 1982 to 1986, spontaneous bacterial peritonitis wasdiagnosed in 38 consecutive hospitalized cirrhotic patients (positive ascites culture and polymorphonuclear cell concentrations greater than 250 cells per mm3). Twenty-five patients recovered from their infection (69 p. 100) in a mean time of 9 ± 7 days. The cumulative survival was 68 p. 100 at one week, 50 p. 100 at one month, and 25 p. 100 at one year. The best independant prognostic factors for lack of cure from peritonitis were a low ascitic pH value (p < 0.001), an elevated serum creatinine level (p = 0.001), an elevated serum creatinine level (p = 0.01) and the presence of hepatocellular carcinoma (p < 0.05). The best prognostic factors for death were low ascitic pH value (p = 0.001) and gastrointestinal hemorrhage (p = 0.005). A low ascitic pH value was correlated with other signs of severe infection (signs of generalized infection, ongoing infection during the first week after diagnosis), with signs of severe liver disease (encephalopathy, hepatocellular carcinoma) or severe renal dysfunction (high serum creatinine level, low arterial pH value). Because of the late high-death rate associated with spontaneous bacterial peritonitis, liver transplantation should be considered in these patients.