Emergency departments (EDs) are high-risk settings for workplace violence, but interventions to prevent violent incidents and to prepare staff are not yet consistently implemented, and their effectiveness is often unclear. This study aims to summarise evidence on workplace violence prevention interventions that were implemented in EDs to reduce violent incidents caused by patients/relatives or to increase the knowledge, skills or feelings of safety of ED staff. A systematic review was conducted. The databases MEDLINE, Web of Science, Cochrane Library, CINAHL and PsycINFO were searched for studies dated between January 2010 and May 2021. Interventional and observational studies reporting on behavioural, organisational or environmental interventions among healthcare workers in hospital EDs were included. Studies were assessed for methodological quality using the Johanna Briggs Institute Tools. Key findings of studies were summarised narratively. Fifteen studies were included, of which eleven examined behavioural interventions (classroom, online or hybrid training programmes) on de-escalation skills, violent person management or self-defence techniques. Four studies included in addition, organisational and environmental interventions. Most studies showed that interventions had a positive effect in the form of a reduction of violent incidents or an improvement in how prepared staff were to deal with violent situations; however, evidence is still sparse. Further studies should consider in particular, environmental and organisational interventions and ensure a high methodological quality.