This article examines how Brazilian nationalist elites perceived Jews, Judaism and Zionism during the military dictatorship period (1964–1985). Although an explicit antisemitic discourse was socially unacceptable in Brazil, many nationalist officials and intellectuals who discussed Jewish and Zionist Brazilians among themselves during those years were using a discourse of Jewish disloyalty. This discourse depicted Jews who adopted a diasporic stance (maintaining certain ethnic and national boundaries and supporting the State of Israel) as not loyal enough to Brazil. Tracing the history of this discourse, the article shows that it was inspired and informed by particular Brazilian notions of race, ethnicity and diaspora, and especially the national narrative of racial democracy. As such, it was a uniquely Brazilian discourse, even as it shared several common characteristics with how Jews were perceived and discussed in other countries. This is illustrated by comparing the Brazilian and Argentine nationalist discourses of Jewish disloyalty.