Introduction Injury is the most common reason for admission to hospital in people with dementia in Australia. However relatively little is known about the temporal trends and the hospital experience of people with dementia hospitalised for an injury. This population-based data linkage study compared the causes, temporal trends and health outcomes for injury-related hospitalisations in people with and without dementia. Methods Hospitalisation and death data for 235,612 individuals aged 65 years and over admitted to hospital for an injury over the ten year period (2003-2012) in New South Wales, Australia were probabilistically linked. Descriptive statistics including chi square tests, observed and age-standardised admission rates and rate ratios (RRs) were calculated. Trends over time were analysed using negative binomial regression. Results There were 331,432 injury-related hospitalisations over the study period. Both the observed (RR 3.16; 95% CI 3.13-3.19) and age-standardised admission rate ratios (RR 1.78; 95% CI 1.77-1.79) were higher for people with dementia. Age-standardised rates increased by 3.5% (95% CI 3.1-3.9) per annum over the study period for people without dementia. In contrast, for people with dementia, rates increased by 2.4% (95% CI 1.8-3.1) per annum until 2007 and then decreased by 3.1% (95% CI -4.4 to -1.7) per annum from 2007 onwards. Compared to people without dementia, a higher proportion of people with dementia were hospitalised as a result of a fall (90.9% vs 75.2%, p < 0.0001), sustained a fracture (57.2% vs 52.1%, p < 0.0001), notably hip fracture (30.7% vs 14.7%, p < 0.0001), had longer mean hospital lengths of stay (LOS) (16.5 vs 13.6 days), and higher 30-day mortality (8.7% vs 3.6% p < 0.0001), although this pattern was not consistent across all injury types. Conclusions People with dementia are disproportionately represented in injury-related hospitalisations, experience longer hospital LOS and have poorer outcomes. Ninety percent of hospitalisations for people with dementia were as a result of a fall, highlighting the importance of developing and implementing effective fall-related preventive strategies in this high risk population.