The Italian regional elections of 3–4 April 2005 were a major victory (11-2) for the centre-left The Union coalition, led by Romano Prodi. The centre-right coalition, governing in the national government, was defeated in all the regions it held, except for its strongholds in Lombardy and Veneto, whose population is anyway a fourth of Italian population. The elections resulted in the national government, led by Silvio Berlusconi, to acknowledge defeat and open a crisis, which resulted in the formation of Berlusconi III Cabinet, with some ministers being substituted.
Due to a series of bureaucratic issues involving the presentation of the list of Social Alternative in Basilicata, the election there would have been held two weeks later. There, the victory of the centre-left coalition brought the tally to 12-2.
The fact that the centre-left was particularly strong in small regions led to the even result of the 2006 general election.