The public tender is the way for Brazilians and foreigners to access the public positions of the direct and indirect public administration. Federal Law 12,990 establishes the reserve of 20% of vacancies for blacks in federal public tenders. Through the deductive and bibliographic method, the study starts understanding affirmative actions, to later analyze the constitutionality decision of Law 12.990, and finally to verify if through its use it is affirming citizenship or falling into a reverse discrimination, this being the purpose of the study. It can be concluded that, even if there are opposing and favorable discussions, the quotas consist of a citizenship exercise, as regards the union of critical forces so that the rights are guaranteed and made feasible. However, it does not correct racial inequality, since part of the black population remains distant from opportunities to improve its social status.