BACKGROUND To investigate the clinical characteristics, outcome, and prognostic factors related to mortality in patients with Escherichia coli liver abscess. METHODS We retrospectively analyzed 72 patients aged 18 years and older who were diagnosed as having E. coli liver abscesses from July 1996 to June 2002 at two medical centers in Taiwan. RESULTS The overall mortality rate was 26.4%. The majority of E. coli liver abscesses was solitary, involved the right lobe of the liver, and comprised polymicrobial infections. The cause of the liver abscess involved the biliary system in 48 patients (66.7%). The most common concomitant diseases were diabetes mellitus (30.6%) and underlying malignancy (30.6%). Metastatic infection was found in 4 patients (5.6%). Multivariate analysis revealed that underlying malignancy (p = 0.034), profound hypoalbuminemia (<2.5 g/dl) (p = 0.008), and multiple abscesses (p = 0.004) were the most significantly prognostic factors for mortality. CONCLUSIONS The predominant causes of E. coli liver abscess were biliary diseases. This report also highlights that E. coli liver abscess has a relatively high mortality rate, which is associated with underlying malignancy, multiple abscesses and profound hypoalbuminemia.