In this study, we applied an ecosocial semiotic theoretical framework to the analysis of graffiti literacies in the Vila Madalena neighborhood of Sao Paulo, Brazil, to inquire about the nature and processes of "conscientizacao" (critical awareness) for adult street dwellers who had no or little ability to read and write (as traditionally defined). An ecosocial semiotic framework suggests that people shape their environment through the use of signs, and these signs in turn shape them as part of the complex, dynamic, and nonlinear process in which the environment and its meanings are actively coproduced. We interviewed five adults in the neighborhood community regarding their thoughts about and experience of graffiti. We also interviewed two of Sao Paulo's renowned urban interventionists (a graffiti gallery owner and a graffiti artist) concerning how they perceived the social and political role of graffiti in the community. Findings indicate that certain ecosocial semiotic features of graffiti art are particularly helpful in providing opportunities for "conscientizacao" to take place for the participants we interviewed. The interventionists expressed a deliberate desire to influence the social and political consciousness of community members, which they also hoped would lead to social action. All participants suggested that graffiti has become an important resource in the community, helping members engage in critical perspectives of both the immediate and distal worlds around them. Overall, examining the nature of graffiti literacy in Sao Paulo, how it is constituted, and how it affects community members is revealing as a process of "conscientizacao" that may have important implications for broadening understandings of praxis. (Contains 1 table and 12 figures.)