The neoliberal restructuring of agriculture is often predicated on the promise of a more efficient food system: other objectives, such as access to food, the environmental sustainability of production practices, the nutritional composition of diets and the rights of food producers, are largely ignored. In this paper, I document how the liberalization of trade and agricultural policies in Guatemala has undermined the latter set of objectives, thereby compromising domestic food sovereignty and global food security. In particular, I demonstrate how neoliberal policies have undermined maize agriculture and contributed to the loss of crop genetic resources in the Guatemalan ‘megacentre’ of agricultural biodiversity. In its place, small‐scale farmers have been encouraged to conform to the country's purported comparative advantage in non‐traditional export crops. The results have been widening inequality, a growing dependence upon imported grain and agrochemicals, environmental degradation and decreased food security.