Ethnic Studies courses are expanding in U.S. schools. While research has demonstrated the benefits of Ethnic Studies for racially minoritized students, less research has interrogated the process of Ethnic Studies curriculum development. Counternarrative--a central component of Ethnic Studies curricula--may present tensions for teachers crafting Ethnic Studies curricula. Through a case study of Ethnic Studies curriculum development with experienced teachers in a large urban school district, this article illuminates three tensions in designing Ethnic Studies curriculum with counternarrative in mind. Tensions regard argumentation, choosing among counternarratives, and literacy development. Counternarrative is essential to Ethnic Studies instruction and a core component of education for racial justice. Exploring how teachers navigate the tensions in moving from counternarrative to curriculum represents an important inquiry into Ethnic Studies curriculum development.