The transformation of urban space constitutes one of the most dynamic aspects of the Islamist movement. Prevalent models have accounted for this phenomenon by referring to the rural immigrants' capacity for autonomous network building or their creative subjectivities. This article analyzes Islamization by studying the interactions between Islamists and the residents in a poor district in Istanbul. It demonstrates not only that the urban poor are indeed active in forming communities and subjectivities but also that their agency is shaped (and ultimately absorbed) by the Islamist project. It is Islamism as political practice and not solely the dynamism of civil society that lies at the root of the city's religious transformation. Nevertheless, Islamism becomes influential because it is able to link civil society and urban subjectivity to its project. These arguments are based on a two-year-long ethnography and fifty interviews.