Drawing on the authors' experience in the international Campbell Collaboration, this essay presents a principled and pragmatic approach to evidence-informed decisions about child welfare. This approach takes into account the growing body of empirical evidence on the reliability and validity of various methods of research synthesis. It also considers wide variations in the cultural, economic, and political contexts in which policy and practice decisions are made--and the contexts in which children live and die. This essay illustrates the use of Campbell and Cochrane systematic reviews to inform child welfare decisions in the diverse contexts that exist around the globe.