Background: Screening in the emergency department (ED) can identify individuals in need of targeted assessment and early intervention in the hospital or community setting. Time pressures, inadequate resources, poor integration of screening tools into clinical workflow and lack of staff training are barriers to successfully implementing screening in the ED. Tailored implementation processes and education programmes were identified as facilitators. The aim of this QES is to synthesise evidence pertaining to the barriers and facilitators to implementing screening in the ED. This review will focus on the experience of healthcare workers (HCWs) who are involved in this process. Methods: A comprehensive literature search will be completed in Scopus, CINAHL, Medline, Embase, Pubmed and Cochrane library. Grey literature sources will be searched and include Open Grey, Google Scholar, Lenus Irish Health Repository, Science.Gov and Embase Grey Literature. Qualitative or mixed methods studies that include qualitative data on the experiences of HCWs will be included. “Best fit” framework synthesis will be utilised to produce a context specific conceptual model to describe and explain how these barriers and facilitators may impact on implementation. An a priori framework of themes, formed from the existing evidence base, will inform the ultimate thematic analysis and assist in the organisation and interpretation of search results, ensuring the QES is built upon current findings. CASP will be utilised to quality appraise articles and GRADE CERQual will assess confidence in the QES findings. The screening, quality appraisal, data extraction and assessment of confidence in findings will be completed by two reviewers independently and in duplicate. Contingencies for conflict management during these processes will be outlined. Conclusions: This synthesis, will offer a new conceptual model for describing healthcare workers’ experience of the barriers and facilitators that impact on the implementation of screening tools in the ED. Registration: PROSPERO CRD42020188712 05/07/20