[Excerpt from authors] This report provides a synthesis of the best available evidence in the area of nurse staffing and patient safety. It also gathers policy recommendations in the area. Three questions guided the synthesis, which was based on 73 major research studies and several reviews: 1) Do decisions about nurse staffing make a difference to patient safety? How and why? 2) What attributes or other contextual factors have been found to show an effect on nurse staffing and/or patient safety? 3) What knowledge exists around the implementation of good staffing initiatives?