This article examines charter schools from the perspective of religious institutions and parents that may want to open such schools. Religion-based charter schools also pose unique policy and legal questions because charter schools are a singular reform method. It examines the relevant, recent and historical, legal cases, and relevant examples of charter schools that relate to religions in some way. It also provides a chart to provide the reader with a general understanding with what activities are and are not permitted by the United States Constitution. Because the Establishment Clause draws a line that is far from clear, any list of permissible and non-permissible activities of faith-based charter schools is discussed in broad strokes. (Contains 1 figure.)