The island of Sicily, Italy, and its main city, Palermo, appear an ideal scenario for sustainable food provisioning: the former being the first region in Italy for organically cultivated land, the latter Italy's fifth largest city. This article explores ideals and practices of sustainable urban food systems through an example of environmental consumer activism in Palermo. It does this by narrating the story of an organic farmers' market created by citizens and producers. The article reflects critically on understandings of food-related ‘sustainability’ held by the actors involved, showing the difficulties of operationalizing the concept for qualitative, socio-cultural research. It also highlights the potential of grass-roots activism among consumers and farmers. With particular reference to the Palermitan context, this potential runs counter to an enduring image of the southern Italian region as a place where civil society initiatives are wanting. By analyzing the market's history from its inception to its demise due to difficulties with the center-right-wing municipality, the article shows that it is the political element, rather than the cultural one, that often constrains grass-roots activism in Sicily. These problems of power and political representation raise a crucial question: can a consumer mobilization become a tool for social and environmental transformation in locales where institutions are not already favorably disposed, at least to a certain degree, to the values of such mobilization?