While the People's Party (PP) of Alberto Ruiz-Gallardón was widely expected to win a second term and expand its absolute majority in the Assembly of Madrid—with opinion polls predicting a comfortable victory with as many as 59 seats—its gains ended up being minimal.

The extremely low turnout, one of the lowest in a regional election, benefitted the opposition Spanish Socialist Workers' Party (PSOE) instead, which saw a strong performance as a result at the expense of the United Left (IU), which lost half of its votes and seats.

[2] Voting for the Assembly was on the basis of universal suffrage, which comprised all nationals over 18 years of age, registered in the Community of Madrid and in full enjoyment of their political rights.

All members of the Assembly of Madrid were elected using the D'Hondt method and a closed list proportional representation, with an electoral threshold of five percent of valid votes—which included blank ballots—being applied regionally.

[2][3][4] The president had the prerogative to dissolve the Assembly of Madrid and call a snap election, provided that no motion of no confidence was in process, no nationwide election was due and some time requirements were met: namely, that dissolution did not occur either during the first legislative session or within the legislature's last year ahead of its scheduled expiry, nor before one year had elapsed since a previous dissolution.

[8] Investiture processes to elect the President of the Community of Madrid required for an absolute majority—more than half the votes cast—to be obtained in the first ballot.