The term of the Parliament of Galicia expired four years after the date of its previous election, unless it was dissolved earlier. The election decree was required to be issued no later than the twenty-fifth day prior to the date of expiry of parliament and published on the following day in the Official Journal of Galicia, with election day taking place between the fifty-fourth and the sixtieth day from publication. The previous election was held on 21 October 2001, which meant that the legislature's term would have expired on 21 October 2005. The election decree was required to be published in the DOG no later than 27 September 2005, with the election taking place up to the sixtieth day from publication, setting the latest possible election date for the Parliament on Saturday, 26 November 2005. The president had the prerogative to dissolve the Parliament of Galicia and call a snap election, provided that it did not occur before one year had elapsed since a previous dissolution under this procedure. In the event of an investiture process failing to elect a regional president within a two-month period from the first ballot, the Parliament was to be automatically dissolved and a fresh election called.
Parties and candidates
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, whereas groupings of electors needed to secure the signature of at least one percent of the electorate in the constituencies for which they sought election, disallowing electors from signing for more than one list of candidates. Below is a list of the main parties and electoral alliances which contested the election:
Opinion polls
The table below lists voting intention estimates in reverse chronological order, showing the most recent first and using the dates when the survey fieldwork was done, as opposed to the date of publication. Where the fieldwork dates are unknown, the date of publication is given instead. The highest percentage figure in each polling survey is displayed with its background shaded in the leading party's colour. If a tie ensues, this is applied to the figures with the highest percentages. The "Lead" column on the right shows the percentage-point difference between the parties with the highest percentages in a given poll. When available, seat projections are also displayed below the voting estimates in a smaller font. 38 seats were required for an absolute majority in the Parliament of Galicia.
