In this study, we evaluated the implementation of small learning communities (SLCs) in a large urban K-12 school district. Using case study methods, we examined three unique high schools implementing their distinct SLC models guided by a district plan. We investigated conditions and structures that supported, and presented challenges to, successful implementation. While our sample schools represented various levels of success, our data revealed some common findings across sites: successful implementation of SLCs requires strong school leadership willing to grant sufficient autonomy to SLCs, meaningful teacher collaboration, and professional development aligned with SLC goals. Other key findings included an increase in personalization among all schools implementing SLCs, but challenges with achieving true equity and parent engagement. The case study approach provided an in-depth understanding of the contextual factors that influence a large-scale educational reform effort, and provided lessons to schools and districts attempting similar interventions. #QualitativeMethods #2011Conference #CaseStudyMethods #Prek-12EducationalEvaluation