ABSTRACTThe article focuses on the Italian general election held on 4 March 2018, which was notable for the surprising results in southern Italy. These results will be analysed by looking at two dimensions of electoral behaviour: on one hand, participation and volatility, on the other the success of the protest parties, the Five Star Movement (M.5.S.) and the League. These features will be considered in relation to the territorial distribution of the vote. More specifically, in the 2018 election participation was exceptionally high, especially in the south which in some regions saw electors returning to the polls. But electoral volatility is still high. Both factors affected the extraordinary success of new protest parties and collapse of the traditional parties. Traditionally in the south the vote has gone to moderate and pro-government parties, but this time in all constituencies the M.5.S., an ‘eccentric’, protest or populist party-movement, which in many cases took over 40 per cent of the votes, with a peak of 50 per cent in Campania and Sicily. Further, the wave of protest votes favoured another party with no previous support in this geographical area, the League. It may be too soon to say whether these changes in the form and dynamics of the party system are long-lasting and able to achieve a lasting change in the political spectrum, but so far the outcome of election has given a further push to the radicalization of both electoral demand and supply.