Interventions that aim to promote social competence, reduce problem behavior, and improve school climate are common at all levels of schooling. This whole-school focus, coupled with researchers' concerns about contamination or spillover effects in evaluations that randomly assign classrooms or students to conditions, as well as advances in statistical modeling, have resulted in an increased emphasis on the use of cluster-randomized trials in education settings. That is, evaluation of educational interventions often entails random assignment of schools, rather than classrooms or individual students, to intervention and treatment-as-usual groups. Such evaluations present unique methodological challenges with respect to the recruitment of schools and the choice of methods to ensure equivalence of groups. Furthermore, active consent return rates may be significantly challenged in school based research, particularly in urban, high-risk schools. In this article, we examine issues of school recruitment, equivalence of intervention groups, and consent rates in a sample of 42 schools from 3 sites that participated in the Social and Character Development Research program funded by the Institute of Education Sciences (IES), in collaboration with the Centers for Disease Control and Prevention (CDC). Although differences between sites are apparent, the intervention and comparison groups of schools within each site are shown to be equivalent on both a range of school demographic characteristics and on consent return rates. Implications for conducting randomized evaluations of school-based intervention and prevention programs are discussed. (Contains 1 note and 1 table.)