Results breakdown of the 2004 European Parliament election in Spain

This is the results breakdown of the European Parliament election held in Spain on 13 June 2004. The following tables show detailed results in each of the country's 17 autonomous communities and in the autonomous cities of Ceuta and Melilla.

Electoral system
The 54 members of the European Parliament allocated to Spain as per the Treaty of Nice were elected using the D'Hondt method and a closed list proportional representation, with no electoral threshold being applied in order to be entitled to enter seat distribution. Seats were allocated to a single multi-member constituency comprising the entire national territory. Voting was on the basis of universal suffrage, which comprised all nationals and resident non-national European citizens over eighteen and in full enjoyment of their political rights. The use of the electoral method resulted in an effective threshold based on the district magnitude and the distribution of votes among candidacies.

The electoral law allowed for parties and federations registered in the interior ministry, coalitions and groupings of electors to present lists of candidates. Parties and federations intending to form a coalition ahead of an election were required to inform the relevant Electoral Commission within ten days of the election call. In order to be entitled to run, parties, federations, coalitions and groupings of electors needed to secure the signature of at least 15,000 registered electors; this requirement could be lifted and replaced through the signature of at least 50 elected officials—deputies, senators, MEPs or members from the legislative assemblies of autonomous communities or from local city councils. Electors and elected officials were disallowed from signing for more than one list of candidates.

Congress of Deputies projection
A projection of European Parliament election results using electoral rules for the Congress of Deputies would have given the following seat allocation, as distributed per constituencies and regions (note that results are compared with party totals in the preceding general election—held in March 2004—for consistency):