OBJECTIVE: Despite mild traumatic brain injury (mTBI) accounting for 80% of head injury diagnoses, recognition of individuals at risk of cognitive dysfunction remains a challenge in the acute setting. The objective of this study was to evaluate the feasibility and potential role for computerised cognitive testing as part of a complete ED head injury assessment. METHODS: mTBI patients (n = 36) who incurred a head injury within 24 h of presentation to the ED were compared to trauma controls (n = 20) and healthy controls (n = 20) on tests assessing reaction time, speed and attention, episodic memory, working memory and executive functioning. Testing occurred during their visit to the ED at a mean of 12 h post-injury for mTBI and 9.4 h for trauma controls. These tasks were part of the Cambridge Neuropsychological Test Automated Battery iPad application. Healthy controls were tested in both a quiet environment and the ED to investigate the potential effects of noise and distraction on neurocognitive function. RESULTS: Reaction time was significantly slower in the mTBI group compared to trauma patients (P = 0.015) and healthy controls (P = 0.011), and deficits were also seen in working memory compared to healthy controls (P ≤ 0.001) and in executive functioning (P = 0.021 and P < 0.001) compared to trauma and healthy controls. Performances in the control group did not differ between testing environments. CONCLUSION: Computerised neurocognitive testing in the ED is feasible and can be utilised to detect deficits in cognitive performance in the mTBI population as part of a routine head injury assessment.