The Department of Health recently published a document entitled a Framework for Safe Nurse Staffing and Skill Mix in Ireland. In this report a number of recommendations were made to ensure that the staffing of hospitals was safe and effective; that is to ensure the right number of nurses are in the right place at the right time and with the right skills to deliver care. This research intends to measure the extent to which the recommendations in this report on ensuring safe nurse staffing are impacting on patients and staff in hospitals and emergency departments (EDs). The research also examines how much the recommendations cost to implement. We will measure a number of factors that we know are related to nurse staffing. These include missed care, which is looking at work that nurses may not have had time to complete, as well as how satisfied patients are with their care. We will look at whether changes in staffing will impact on the experience of patients in EDs, such as the length of time waiting for care. Based on our findings, we will make a number of recommendations to improve the staffing of wards and emergency departments in Ireland.