The objective of this paper is to provide some practical insight into the process of implementing large-scale randomized controlled trials (RCT) in educational settings and to provide general recommendations for researchers conducting education-based RCTs in the future. The authors draw their recommendations from their recent experiences implementing RCTs in classroom settings for four Department of Education-funded evaluations. This paper highlights the complexity of, and the lessons learned from, implementing large-scale experimental evaluations in real world contexts.