This article outlines a mixed methods approach to systems change evaluation and offers a case study of how this approach has been used to evaluate the development of system infrastructure supporting the implementation, spread, and sustainability of evidence-based home visiting projects. The approach combined systems concepts (boundaries, relationships, perspectives, ecological levels, and dynamics) and qualitative methods (project site visits, telephone interviews, reviews of project documents, and logic models) with quantitative methods (a web-based partner survey to measure the projects' system properties and contextual dynamics) to assess how these system factors were associated with the projects' infrastructure development.