Background: pyogenic liver abscess (PLA) is a potentially life-threatening disease in middle-to-old aged persons. Objective: to compare the differences in clinical features and outcomes between older and younger PLA patients, and to identify predictors of outcomes in older patients. Design: retrospective chart review of all PLA patients between July 1999 and June 2007. Setting: a 1,600-bed primary and tertiary care centre. Subjects: in total, 339 patients were enrolled and included 118 ā„65 years of age (the elderly group) and 221 patients <65 years of age (the non-elderly group). Methods: clinical features, laboratory, imaging and microbiologic findings, treatment and outcomes for each of the included patients were collected. The predictor of outcome was determined using logistic regression and purposeful selection of covariates. Results: the elderly group had a higher APACHE II score on admission, a biliary abnormality, a malignancy, a pleural effusion, polymicrobial, anaerobic or multi-drug-resistant isolates, inappropriate initial antibiotics, a longer hospitalisation and a longer parenteral antibiotic treatment period than the non-elderly group, whereas the non-elderly group was more likely to be alcoholic men with cryptogenic origin of abscess and Klebsiella pneumoniae infection. There was no difference in case fatality between the elderly (13.6%) and non-elderly (8.6%) groups despite the elderly group having a poorer host status on admission. In multivariate analysis, age (P = 0.028) and APACHE II score at admission ā„15 (P = 0.001) were risk factors, but K. pneumoniae infection (P = 0.012) was a protective factor for fatality in older PLA patients. Conclusions: these data suggest that older PLA patients wound have a fair outcome compared to younger patients, but require longer hospitalisations.