Across the world, university teachers are increasingly being required to engage with diversity in the classes they teach. Using the data from a large Economics 1 class at a South African university, this attempts to understand the effects of diversity on chances of success and how assessment can impact on this. By demonstrating how theory can be used to understand results, the paper aims to encourage university teachers to adopt proactive strategies in managing diversity, rather than simply explaining it using student characteristics. (Contains 3 tables and 2 figures.)