Background: Social worker input into hospital emergency department (ED) services would appear to be central to the provision of effective, durable and comprehensive services. Unfortunately, there are few literature overviews to summarise this potential. Methods: A practice-based scoping review was conducted to identify the role and potential of social worker involvement in emergency department settings. After initial screening, abstracts of 252 articles were read and screened, resulting in 37 articles, which were reviewed and thematically analysed by pairs of reviewers, and also appraised for quality and relevance. Results: Three key practice areas of social work involvement in emergency departments were identified: mental health, suicide risk and crisis, and chronic disease. Details of social work involvement in each key practice area as noted in the literature were outlined. Beyond this, two priority focus areas were also noted: social work screening and assessment in ED, and developing a social work model that is relevant to ED. Conclusion: The identified key practice areas and priority focus areas provide a useful guide for practitioners (to more clearly define their assistance and interventions in ED), and for managers and academics (to more clearly guide the development of social work policy, practice and staffing models in ED settings).