The article attempts to trace the origins and to assess the extent ofparty-system change in Italy in the 1990s. It also examines some hypotheses on the possible causes of such changes. Building on research on anti-party sentiment and on changes in party organization the paper begins with an analysis of the evolution of the party system in the last 30 years which identifies organizational adaptation as a delaying factor in party system change. This is followed by a description of the party system after the 1994 elections based on generally accepted party system characteristics and indicators (volatility, number ofparties, ideological distance). The assessment is made difficult by the, perhaps temporary, coexistence of two party-systems, respectively relevant for electoral and inter-election competition. The evidence however, suggests, that party-system transformation is under way, while it might still be inappropriate to talk about structural change. Degeneration of parties and a deep institutional crisis appear to be the factors leading to the explosion of pent-up alienation and antiparty sentiments, and to demands for institutional and constitutional change that preceded and appeared to be the immediate causes of party system transformation.