Urban conflicts are increasingly visible in the political processes of advanced capitalist societies. There are more and more grassroots movements arising out of urban contradictions. But the theoretical and practical question to be answered is: under which conditions do these movements become agents of social change? This article tries to make some progress in this direction by: 1 Presenting a theoretical framework for the study of urban social movements. 2 Observing 180 urban struggles in the Paris metropolitan area (between 1968 and 1973), classifying them into a set of variables and finding some meaningful relationships. 3 Relating the main trends of these urban movements to the evolution of the political situation in France and, particularly, to the transformation of left‐wing strategy. The main argument is that the urban movements become crucial because they are a major element in the political and ideological hegemony—beyond the boundaries of the industrial working class—which the Left must overcome to go forward in the democratic path to socialism.