Rapidly changing demographics challenge education systems everywhere. Multilingualism, in particular, brings challenges in curriculum, pedagogy and assessment. Here we draw attention to contexts and practices of multilingual education in southern settings that differ from those in northern ones. Whereas much of the literature indicates that multilingual assessment is necessary for reasons of social justice and equity, it remains either elusive or contained to minority communities in Europe and North America. The purpose here is to draw attention to a century of system-wide bilingual and multilingual education policies, practices and assessment in South Africa. The bi-/multilingual design of large-scale assessment measures student knowledge in two or three languages (as conventionally understood). Although not anticipated in policy, it also permits students to make use of their bilingual or multilingual repertoires in high-stakes examinations. We demonstrate that, while challenging to design and administer, students' multilingual repertoires can be brought into the design of large-scale assessment. System-wide use of bi-/multilingual assessments can also address concerns of equity and social justice. Longitudinal data from system-wide assessment further indicate that code-switching and translanguaging are promising only when used to increase students' repertoires for both horizontal purposes and vertical access to language/s of power.