1999 Castilian-Leonese regional election

The 1999 Castilian-Leonese regional election was held on Sunday, 13 June 1999, to elect the 5th Cortes of the autonomous community of Castile and León. All 83 seats in the Cortes were up for election. The election was held simultaneously with regional elections in twelve other autonomous communities and local elections all throughout Spain, as well as the 1999 European Parliament election.

Electoral system
The Cortes of Castile and León were the devolved, unicameral legislature of the autonomous community of Castile and León, having legislative power in regional matters as defined by the Spanish Constitution and the Castilian-Leonese Statute of Autonomy, as well as the ability to vote confidence in or withdraw it from a regional president. Voting for the Cortes was on the basis of universal suffrage, which comprised all nationals over 18 years of age, registered in Castile and León and in full enjoyment of their political rights.

All members of the Cortes of Castile and León were elected using the D'Hondt method and a closed list proportional representation, with an electoral threshold of three percent of valid votes—which included blank ballots—being applied in each constituency. Seats were allocated to constituencies, corresponding to the provinces of Ávila, Burgos, León, Palencia, Salamanca, Segovia, Soria, Valladolid and Zamora, with each being allocated an initial minimum of three seats, as well as one additional member per each 45,000 inhabitants or fraction greater than 22,500.

As a result of the aforementioned allocation, each Cortes constituency was entitled the following seats:

The use of the D'Hondt method might result in a higher effective threshold, depending on the district magnitude.

Election date
The term of the Cortes of Castile and León expired four years after the date of their previous election. Elections to the Cortes were fixed for the fourth Sunday of May every four years. Legal amendments introduced in 1998 allowed for these to be held together with European Parliament elections, provided that they were scheduled for within a four month-timespan. The previous election was held on 28 May 1995, setting the election date for the Cortes concurrently with a European Parliament election on Sunday, 13 June 1999.

After legal amendments earlier in 1999, the president was granted the prerogative to dissolve the Cortes of Castile and León 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. In the event of an investiture process failing to elect a regional president within a two-month period from the first ballot, the Cortes were to be automatically dissolved and a fresh election called. Any snap election held as a result of these circumstances would not alter the period to the next ordinary election, with elected procurators merely serving out what remained of their four-year terms.

Parliamentary composition
The Cortes of Castile and León were officially dissolved on 20 April 1999, after the publication of the dissolution decree in the Official Gazette of Castile and León. The table below shows the composition of the parliamentary groups in the Cortes at the time of dissolution.

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 poll. When available, seat projections determined by the polling organisations are displayed below (or in place of) the percentages in a smaller font; 42 seats were required for an absolute majority in the Cortes of Castile and León (43 until 1 January 1999).