The incumbent Mayor of Milan Letizia Moratti was defeated by the left-wing lawyer Giuliano Pisapia, ending 18 years of right-wing rule in the city government.

A number of intellectuals and notable people from the cultural and political elite of Milan immediately expressed their support to Pisapia.

On 14 November 2010 he ran for the open primary election of the centre-left coalition led by the Democratic Party, with the support of Nichi Vendola's Left Ecology Freedom, and unexpectedly won (receiving 45% preferences) despite not being an actual member of the PD:[3] Total voters: 67,499 At the beginning of the campaign, incumbent Mayor Letizia Moratti was thought to be largely advantaged, especially as Milan is traditionally a right-wing stronghold, the homeland of Silvio Berlusconi's party (to which Moratti belongs), as well as a symbol of the alliance between Berlusconi and Umberto Bossi's Lega Nord, a party that promotes a greater independence of Northern Italy.

The semipresidential voting system is used for all mayoral elections in Italy of cities with a population higher than 15,000 for the fifth time.

[7][8][9] The candidate of Beppe Grillo's party Five Star Movement, Mattia Calise, who was only 20 years old, obtained nearly 3.5% of the votes.