Objective: To describe the leading mechanisms of hospitalised unintentional injury in Australian Aboriginal children and identify the injury mechanisms with the largest inequalities between Aboriginal and non-Aboriginal children. Methods: We used linked hospital and mortality data to construct a whole of population birth cohort including 1,124,717 children (1,088,645 non-Aboriginal and 35,749 Aboriginal) born in the state of New South Wales (NSW), Australia, between 1 July 2000 and 31 December 2012. Injury hospitalisation rates were calculated per person years at risk for injury mechanisms coded according to the ICD10-AM classification. Results: The leading injury mechanisms in both groups of children were falls from playground equipment. For 66 of the 69 injury mechanisms studied, Aboriginal children had a higher rate of hospitalisation compared with non-Aboriginal children. The largest relative inequalities were observed for injuries due to exposure to fire and flame, and the largest absolute inequalities for injuries due to falls from playground equipment. Conclusion: Aboriginal children in NSW experience a significant higher burden of unintentional injury compared with their non-Aboriginal counterparts. Implications for Public Health: We suggest the implementation of targeted injury prevention measures aimed at injury mechanism and age groups identified in this study.