Comparative outcomes data are widely used to monitor quality of care in the cardiovascular area; little is available in the respiratory field. We applied validated methods to compare hospital outcomes for chronic obstructive pulmonary disease (COPD) exacerbation. From the hospital information system, we selected all hospital admissions for COPD exacerbation in Rome (for 2001-2005). Vital status within 30 days was obtained from the municipality mortality register. Each hospital was compared to a pool of hospitals with the lowest adjusted mortality rate (the benchmark). Age, sex and several potential clinical predictors were covariates in logistic regression analysis. 12,756 exacerbated COPD patients were analysed (mean age 74 yrs, 71% males). Diabetes, hypertension, ischaemic heart disease, heart failure and arrhythmia were the most common coexisting conditions. The average crude mortality in the benchmark group was 3.8%; in the remaining population it was 7.5% (range 5.2-17.2%). In comparison with the benchmark, the relative risk of 30-day mortality varied widely across the hospitals (range 1.5-5.9%). A large variability in 30-day mortality after COPD exacerbation exists even considering patients' characteristics. Although these results do not detect mechanisms related to worse outcomes, they may be useful to stimulate providers to revision and improvement of COPD care management.