To describe the frequency and nature of deaths from resident-to-resident aggression (RRA) in nursing homes in Australia.National population-based retrospective cohort study.Accredited nursing homes in Australia.Residents whose deaths resulted from RRA and were reported to the coroner between July 1, 2000, and December 31, 2013.Cases were identified using the National Coronial Information System, and data on individual, interpersonal, organizational, and societal factors were collected through review of the paper-based coroners' files.This research identified 28 deaths from RRA over a 14-year study period (0.004 per 100,000 bed days). Most exhibitors of aggression were male (n = 24, 85.7%), and risk of death from RRA was twice as high for male as for female nursing home residents (relative risk (RR) = 2.13, 95% confidence interval (CI) = 0.93-4.80, P = .05). Almost 90% of residents involved in RRA had a diagnosis of dementia, and three-quarters had a history of behavioral problems, including wandering and aggression. Dyad analysis showed that exhibitors of aggression were often younger and more recently admitted to the nursing home than targets. RRA incidents commonly occurred in communal areas and during the afternoon and involved a "push and fall." Seven (25%) RRA deaths had a coronial inquest; criminal charges were rarely filed.This is the first national study in Australia, and the largest internationally, to examine RRA deaths using medicolegal data. This generates hypotheses for future research on the effect of environmental and organizational factors on the frequency and preventability of RRA.