Background Improvement in healthcare, seeking the correct balance between quality and costs, is an ongoing concern in many countries. Many countries have developed and implemented improvement programmes in health care, particularly in emergency departments (ED), which play a key role in terms of hospital resources and planning. The regional government of Sicily implemented a project 2010–2012 to improve ED care quality and patient safety. Purpose This paper aims to evaluate improvements implemented by the Regional Health Authority of Sicily in the 20 main EDs. Method Performance analysis of EDs was conducted on three levels: care quality (standard Joint Commission International evaluation), efficiency in terms of resources and output (by way of interviews and document analysis) and the role of management in efficiently promoting change (presence of a performance monitoring system). Findings The results show improvements in all areas and improved performance in all EDs. There is, however, room for improvement in certain areas, and improvement was not uniformly distributed. Practical implications The quality of local policy and management are key aspects of efficient promotion of performance improvement. Copyright © 2015 John Wiley & Sons, Ltd.