District authorities in the system of communal decentralization, known in many Italian cities as Consigli di circoscrizione (Cdc), were established between the end of the ‘70s and the early ‘80s make the local government closer to citizens and to promote, at the same time, the participation of the latter in the administration of the former. The set up of such district councils was also a move aiming to give real answers to the many questions raised by the urban social movements active in the big metropolitan areas of the Country. This article, starting from the results of some recent studies on the decentralization system within the Commune of Genova, is set to discuss the implications of the establishment and the evolution of Cdc for political parties as well as for citizens’ committees exerting pressure on local authorities. In other terms, it will describe the patterns of institutional and non-institutional political participation prompted by this new layout of local government, considered as an example of change in the political opportunity structure, trying also to verify if these two fields of participation may somehow overlap. With regard to the local case study, where a new system of nine decentralized organs called Municipi was set up in 2007, the following points will be discussed. First, what kind of political actors and what kind of lists participate in the elections to the bodies of the communal decentralization system. In more detail: are they civic or local lists (organized bottom-up) or organized by traditional political parties (top-down)? Second, what kind of relationships are set with these institutions by neighbourhood-based citizens’ committees that choose not to take part in elections at this level directly. Third, the sociographic profile and attitudes of the politicians elected to these bodies, trying to verify whether they are closer to the mainstream political class or, say, to neighbourhood volunteers