This article details the design of a mixed-methods evaluation for a new equity program serving underrepresented and racially minoritized students at a selective-admissions, gifted public secondary school in the U.S. Rooted in culturally responsive and values-engaged approaches, we explain how principles and practices drawn from these approaches informed our decision-making on the evaluation's mixed-methods design and implementation over two years (two cycles of evaluation). These approaches emphasize ensuring inclusivity in participation; calling attention to culture, power, and equity in all evaluation aspects; and fostering dialogue on conceptualizing and operationalizing values like equity. It is not simple to implement these principles and practices in school-based evaluation. In this article, we share a constellation of issues we navigated throughout the evaluation process and our lessons learned.