Using data from the 2010 Census of Brazil, this article quantitatively examines the phenomenon of sibling differences in racial classification. In sum, the findings demonstrate that within-sibling racial heterogeneity occurs in 17-19% of families. The strongest predictor of racial discordance between siblings is racial discordance between parents. Furthermore, within-sibling regression models establish that race exhibits a modest but statistically significant association with some education and labor market outcomes. Most outcomes are not associated with race for siblings aged 15-19, although in families with both sexes, darker females have more favorable educational outcomes, while darker males have less favorable outcomes. In contrast, darker siblings aged 20-25 are less advantaged than their lighter brothers and sisters along a number of dimensions. They have significantly lower education, lower personal income, lower formal employment, and lower occupational status. It is argued that patterns for siblings aged 20-25 may be indicative of individual racial discrimination.