The purpose of this study was to examine influences on the implementation of a school-based comprehensive program for autistic children. Following the conceptual framework suggested by the Exploration, Preparation, Implementation, Sustainment (EPIS) model, variables from the outer context, inner context, and also that were part of the comprehensive program were explored. An index approach was employed for assessing implementation. The study was part of a larger cluster randomized control trial and took place in 39 elementary schools in a southeastern state within the United States. Variables associated with implementation were transformational leadership style of the principal, percentage of students in the school who were white, and adequacy of coaching. Implications for practice and future research were identified.