Following the theoretical and methodological principles of Variationist Sociolinguistics, this paper analyzes the use of the aspirated variant of postvocalic /s/ by residents of City of God, a predominantly-black neighborhood in Rio de Janeiro that is widely known as a favela (roughly, shantytown or slum). The analyzed data consist of seventeen sociolinguistic interviews conducted in 2015 with twenty-two residents of this community. The quantitative analysis included six social variables—race/color, regional origin, age, gender, education, and speaker—as well as six linguistic variables—preceding vowel, following sound, syllabic stress, number of syllables, grammatical category, and word. Race/color, age, and all the linguistic factors considered in the analysis were selected as statistically significant to the occurrence of /s/ aspiration. This study indicates a possible connection between aspiration and race/color and stresses the importance of including racial identity as a relevant factor in sociolinguistic studies in Brazil, especially those focusing on favelas and other similar urban communities.