Peer review of surgical deaths can identify deficits in individual and systemic delivery of healthcare, ultimately informing quality improvement.From 2008 to 2016, cases reported to the Australia and New Zealand Audit of Surgical Mortality were analysed. Variables associated with peer-judged adverse events were sought.Of 21 045 cases evaluated, 24.8% incurred at least one adverse event judgement. The proportion of cases with reported adverse event significantly decreased over time. Following adjustment for demographic and clinical characteristics, significant negative patient-related associations were advanced age, greater American Society of Anesthesiologists grade, and neurological and malignant comorbidities. Significant associations were also found with systemic or organizational factors, including state/territory, surgical specialty and hospital regionality.Examination of this peer-reviewed database revealed systemic or organizational predictors of adverse events that may have implications for quality improvement at an institutional or jurisdictional level. The extent to which these associations are due to the peer-review process itself should be the focus of further research.