The recent adoption of race-targeted public policies makes Brazil an insightful place to study the social construction of race. This article estimates the effect of racial quotas in college admissions on patterns of racial identification. The authors collected data on persons who matriculated before and after the implementation of quotas at the University of Brasilia, which reserved 20% of admissions slots for persons who self-identified as black. A baseline survey was conducted during college and a follow-up survey was conducted post-college. In sum, the findings suggest that racial quotas had inspired a persistent shift in racial identification from non-black to black and from lighter to darker racial categories. As a whole, the evidence indicates that the policy induced race-making boundary effects, which broadly confirms the insights of social constructionist theories.