During the past 15 years, the Casc Antic, a traditionally low-income and immigrant neighborhood in Barcelona, has been the site of community-based mobilization to revitalize abandoned areas and improve local environmental conditions. The organization of residents and their supporters is situated within a broader context of urban political and socioeconomic change — the transformation of the urban economy into a decentralized, global and technology- and service-focused system, accompanied by rising socioeconomic inequality and displacement in inner-city areas. To date, few studies in the urban environmental arena have been placed within processes of urban change and offer specificity on the purposes, intents and goals that poor and minority residents develop as they understand, resist and challenge their marginality. Why do residents of marginalized neighborhoods and their supporters organize to proactively improve livability and environmental quality? To what extent do the environmental struggles of marginalized communities serve as means to advance more complex political agendas in the city? Through the examination of neighborhood organization for livability in the Casc Antic, I analyze how activists use their environmental endeavors as tools to address stigmas attached to their place, control the land and its boundaries, and build a more transgressive form of democracy.