Background: The significance of vascular access devices for patients in the emergency department (ED) is undeniable. When it comes to evaluating the effectiveness of interventions, randomised controlled trials (RCTs) stand out as the most reliable sources of evidence compared with other study designs. Aim: To explore and synthesise the findings from RCTs related to vascular access devices in the ED setting. Methods: A systematic search will be conducted in electronic medical databases including the Cochrane Central Register of Controlled Trials, Pubmed, CINAHL and Embase databases. All RCTs focusing on peripheral intravenous catheters, central venous catheters and intraosseous catheters, published in English and Chinese in peer-reviewed journals within the past decade, will be included. Conclusion: This scoping review will summarise the current state of evidence for vascular access devices in the ED setting. This will identify gaps in the literature and, in turn, assist clinicians and researchers in pinpointing areas for future exploration and provide a valuable guide for future research.