Over the past three decades, there has been a notable increase in studies of practice change interventions in long-term care (LTC) settings. This review, based on a modified realist approach, addresses the following questions: What practice change intervention characteristics work? And, in what circumstances do they work and why? A modified realist approach was applied to identify and explain the interactions among context, mechanism, and outcome. We searched electronic databases and published literature for empirical studies of practice change interventions that (a) were conducted in LTC settings, (b) involved formal care staff members, and (c) reported a formal evaluation. Ninety-four articles met the inclusion criteria. Interventions that included only predisposing factors were least likely to be effective. Interventions that included reinforcing factors were most likely to produce sustained outcomes. We concluded that interventions aimed at practice change in LTC settings should include feasible and effective enabling and reinforcing factors.