<p>Children presenting with injuries to hospital emergency departments should be screened and assessed for child maltreatment. While child maltreatment screening tools are reliable, their practical implementation and long-term sustainability remain challenging. This implementation study aimed to assess the clinical utility of a child maltreatment E-Checklist across two rural hospitals with mixed adult and paediatric emergency departments, and two metropolitan paediatric hospital emergency departments in New South Wales, Australia. Staff questionnaires (n = 131) and in-depth interviews (n = 15) informed the development and implementation phases. Data from 16,589 electronic medical records, 6,858 pre-intervention and 9731 post-intervention, were analysed to assess E-Checklist completion rates and child maltreatment documentation. A deductive thematic analysis of in-depth interview data highlighted the need to attend to (a) E-Checklist utility and precision, (b) professional development of key stakeholders, and (c) barriers to implementation. Pre-intervention, clinicians demonstrated high professional self-efficacy in child maltreatment reporting but had only moderate expectations of reporting outcomes. Post-implementation, E-Checklist completion and documentation of child maltreatment red flags rose from 1% compliance to as high as 62%. These rates of success varied across sites. The child maltreatment E-Checklist demonstrated strong clinical utility when applied to children under six years presenting with injuries in the emergency department. Across the four sites, child maltreatment documentation and referral processes improved significantly. A collaborative and innovative approach, incorporating real-time consultation with clinicians, proved to be a successful strategy. Additionally, responsiveness to local contexts and the presence of dedicated champions (facilitators) at each site were crucial to the initiative’s success.</p>