Objectives: To compare the characteristics of subdural haematoma (SDH) in children under the age of 2 years, between inflicted, otherwise known as abusive head trauma (AHT), and non-inflicted aetiologies. Methods: This was a retrospective cohort study of 37 cases of SDH in children under the age of 2 years presenting to the ED at an Australian tertiary children's hospital between January 2009 and December 2012 and been assessed by the Child Protection Unit. SDH aetiology was classified into AHT and non-inflicted groups, based on child protection interagency outcome. These groups were compared to determine clinical associations with AHT. Results: Of the 37 infants with SDH, 20 cases were deemed due to AHT, whereas 17 cases were determined to be non-inflicted SDH (15 cases due to accidental trauma and two cases due to congenital benign enlargement of the subarachnoid space). SDH due to AHT was associated with antenatal maternal drug use, previous Department of Child Safety involvement, delayed presentation, history of seizures, floppiness or altered level of consciousness; extracranial findings of fractures, bruising or retinal haemorrhages; radiological findings of >5 mm depth, bilateral, inter-hemispheric blood, posterior fossa blood and diffusion restriction; and outcomes of death or permanent disability. Non-inflicted SDH was associated with witnessed injury, falls and scalp haematoma on imaging. Conclusions: Infant SDH due to AHT accounts for high mortality and morbidity. Early identification of these patients in the ED with referral to specialised units that investigate for potential child abuse is essential.