The purpose of this article is to provide researchers with a framework for promoting high quality mixed methods school-based consultation research. Furthermore, this article is intended for researchers and practitioners interested in evaluating their practice. To meet these objectives, we address quality criteria for quantitative (validity) and qualitative (trustworthiness). From there, we review also multiple schemes for quality (legitimation) criteria in mixed methods and propose a "synergistic participatory approach" that includes legitimation criteria for the integration of qualitative and quantitative work throughout the research process, from conceptualization to dissemination. Our view of integration also applies to the application of findings, which is an idea aligned with participatory processes inherent in our approach to consultation practice. Finally, we discuss and illustrate the application of legitimation criteria to consultation research and evaluation.