This paper frames the role of national assessments in Mexico from the sociology of absences perspective, where the marginalized are actively produced as non-existent. The ENLACE (now PLANEA), as the most publicized Mexican assessment, is analyzed in order to understand how education mechanisms systematically omit the voices and languages of minoritized populations. Using governmental policies and documents, this paper argues that Indigenous children in basic education are intentionally caught in a cycle of assessment inequalities by the institutionalization of one-language, one-culture assessment tools. Overall, the paper advocates for the design of just assessment tools that have clear pedagogical intentions and that can allow the voices of Indigenous children to be heard. A deeper understanding of how the ENLACE is one small yet important fragment of the unequal education system in Mexico could help other institutions in Latin America to revise and revisit their own national assessment tools and consider innovative ways to help Indigenous populations’ voices to be heard.