Ongoing instability in the nursing workforce is raising questions globally about the issue of nurse turnover. A comprehensive literature review was undertaken to examine the current state of knowledge about the scope of the nurse turnover problem, definitions of turnover, factors considered to be determinants of nurse turnover, turnover costs and the impact of turnover on patient, and nurse and system outcomes. Much of the research to date has focused on turnover determinants, and recent studies have provided cost estimations at the organizational level. Further research is needed to examine the impact of turnover on health system cost, and how nurse turnover influences patient and nurse outcomes.