In this paper, we analyse the patterns and trends of group-based inequalities in Brazil in the past 30 years. Using data from the last four demographic censuses (1980, 1991, 2000, and 2010), we estimate numerous measures to analyse inequalities between different 'ethnic' groups. Our results show that the trend toward greater equality in Brazil shown in other analyses of vertical inequality is also found in terms of horizontal inequalities along racial, gender, and regional lines between 1980 and 2010. Nevertheless, horizontal inequalities in terms of race and gender in particular remain pronounced; as shown using various measures, race is highly correlated with income and education. We show that municipalities with low ethnic diversity and low income and education inequality tend to be located in the South region. In regression analysis, we note that ethnic diversity negatively affects the institutional quality of Brazilian municipalities.