Until 2019, Guatemala upheld a de-facto moratorium on GMOs. The ban has been attributed to broad-based social resistance and the unlikely alliances galvanized by the issue. Recent legislation, however, has been met with little resistance. In this paper, I show how the tensions between anti-GM actors and their interactions on the ground help to explain this turn of events in Guatemala, and—more broadly— contributes to our understanding of how biotechnology advances despite significant resistance. Drawing on interviews and ethnographic observation, I demonstrate how urban, professional class Ladinos who oppose GMOs draw on scientific and technical arguments divorced from broader political-economic critiques. Meanwhile, campesino and indigenous activists center their resistance within broader structures of oppression such as colonialism, racism, and capitalism. Specifically, I show how ‘biotechnologizing’ is employed in problematic ways, not only by pro-GMO coalitions—as other scholarship suggests—but also by anti-GM allies. This case contributes to our understanding of how anti-GMO movement frames get constructed in local contexts, and the tensions that arise between anti-GM groups, revealing significant impediments to creating a more just food future in Guatemala.