During the past decade, Catholic leaders have been exploring options to revitalize the faltering Catholic school system especially in urban centers. One route being explored by dioceses and religious orders is opening what have been called "religious charter schools." Though not technically religious schools, they integrate many of the same values and pedagogical approaches as found in faith-based schools. In this article, the authors examined three Chicago public charter schools that are modeled on the successful San Miguel Schools, which are run by the Christian Brothers and are located in impoverished urban areas. After interviewing 40 participants, observing 20 classrooms, and reviewing archival documents, the authors described the challenges faced, tensions experienced, and lessons learned while transferring a Lasallian (Christian Brother) educational model into the public sector.