General elections were held in Serbia, a constituent federal unit of SFR Yugoslavia, in December 1990 to elect the president of Serbia and members of the National Assembly. The presidential election and the first round of the parliamentary elections were held on 9 December, with the second round of the parliamentary elections taking place on 23 December. The elections were scheduled after the ratification of a new constitution on 28 September, which was approved by voters in a referendum held in July. These were Serbia's first multi-party elections, and the only parliamentary election to be held using a two-round voting system with single-member constituencies; all future elections used proportional representation.

Slobodan Milošević came to power in Serbia at the 8th session in 1987. He then led the anti-bureaucratic revolution, which saw his supporters overthrow the leadership of Montenegro, Kosovo, and Vojvodina. After the July 1990 referendum, Milošević's Socialist Party of Serbia (SPS), Vuk Drašković's Serbian Renewal Movement (SPO), and Dragoljub Mićunović's Democratic Party (DS) became registered parties. Due to low requirements, 1,701 candidates ran for parliament and 32 for president. The campaign was marked by intense polarisation and politically driven incidents. SPS inherited a significant amount of political infrastructure upon its formation, giving it an immeasurable advantage over the opposition. Furthermore, SPS controlled most television, radio, and newspapers, which attacked and discredited opponents, especially Drašković, but portrayed SPS as the party of peace. The SPO and Ivan Đurić of Union of Reform Forces during the campaign called for an election boycott over but ultimately dropped after the government agreed to most of their demands in late November.

The primary issue during the campaign was nationalism. SPS and Milošević focused on positive themes and stability, whereas Drašković ran on a nationalist platform. DS and Đurić campaigned on a liberal programme. By the end of the campaign, an SPS supporter had murdered an SPO activist. With a turnout of 71%, primarily due to the Kosovo Albanians' boycott, Milošević won the presidential election in the first round in a landslide, with Drašković placing second. Despite gaining 48% of the popular vote, SPS received 194 out of 250 seats in the National Assembly due to the first-past-the-post electoral system.

The opposition initially claimed electoral fraud in the elections, but eventually conceded. Observers and political scientists reported that electoral irregularities such as ballot stuffing and vote buying took place. After the elections, Dragutin Zelenović became prime minister. His tenure saw Drašković's detention during the 1991 mass protests in Belgrade, the outbreak of the Yugoslav Wars, and the establishment of Federal Republic of Yugoslavia in 1992. Snap elections were then called for December 1992.

Background Post-World War II

After World War II, the Communist Party (later the League of Communists of Yugoslavia, SKJ) consolidated power in Yugoslavia, transforming the country into a socialist state. Each constituent republic had its own branch of the Communist Party, with Serbia having the Communist Party of Serbia, later renamed the League of Communists of Serbia (SKS). With the death of Josip Broz Tito, the leader of Yugoslavia, in 1980, the country was faced with economic issues, constitutional problems, and a rise in ethnic nationalism.

Within Serbia, Slobodan Milošević came to power at the 8th session in September 1987. Milošević served as the president of the League of Communists of Belgrade City Committee until being appointed president of SKS in May 1986 upon the proposal of his mentor Ivan Stambolić, a reformist within SKS. Milošević turned populist in April 1987 and then became a critic of Stambolić. Milošević dismissed Stambolić's allies at the 8th session, and in December 1987, Stambolić was removed as president of Serbia. With Milošević now in power, protests supporting Milošević's policies, known as the anti-bureaucratic revolution, started in Serbia and Montenegro in 1988. Following the protests, the leadership in Montenegro, Vojvodina, and Kosovo was replaced by the pro-Milošević faction.

Milošević was named president of the presidency of the Socialist Republic of Serbia in May 1989, after being nominated to the position by the Socialist Alliance of Working People of Serbia. In response to his appointment, general elections were announced for November 1989. Milošević won the election in a landslide, officially being elected president of the presidency of the SR Serbia. These were the last one-party elections in Serbia. Stanko Radmilović, a Milošević loyalist, became the prime minister of Serbia after the elections.

In January 1990, an SKJ extraordinary congress was held to address the dispute over Milošević's centralisation reforms and reforms of the Federal Assembly of Yugoslavia. During the congress, SKS proposed implementing a "one man–one vote" system, which was opposed by the Slovene delegation, who favoured a confederated Yugoslavia. Milošević was fiercely opposed to confederalism. With the assistance of delegates from Montenegro, Vojvodina, Kosovo, and the Yugoslav People's Army, the proposals from SKS were accepted, while the Slovene and Bosnian proposals were rejected. This ultimately led to the dissolution of SKJ shortly after the congress.

Constitutional referendum

On 13 June 1990, the Democratic Party (DS), Liberal Party (LS), People's Radical Party (NRS), Serbian Renewal Movement (SPO), and Social Democratic Party of Yugoslavia (SDPJ) organised the first opposition protest since World War II. They demanded that free elections be held that year and petitioned for the establishment of a multi-party system. The protest in Belgrade drew between 30,000 and 40,000 people. Radio Television of Belgrade (RTB) covered the protest negatively and the government labelled the protest as "anti-Serbian". During the protest, the police intervened and brutally attacked DS politicians Dragoljub Mićunović and Borislav Pekić. Four cars were damaged during the protests, according to the police, and seven demonstrators were arrested, according to the opposition.

Milošević then unexpectedly announced on 25 June 1990 in the Assembly of the Socialist Republic of Serbia that a constitutional referendum would take place on 1 and 2 July, to determine the new constitution of Serbia. The referendum was held during a crisis in Kosovo. As reported by Zoran Sokolović, the president of the Assembly of SR Serbia, in the Official Gazette, the proposal was recommended by the presidency of SR Serbia and members of the Assembly of SR Serbia.

Prior to the announcement, the government had rejected holding elections in 1990. The government, however, had discussed with the opposition parties on the implementation of a multi-party system. Nevertheless, the discussion was unsuccessful. In response to the announcement, a protest was held at the building of the RTB, criticising the referendum and state controlled media. During the protest, Vojislav Šešelj, the leader of the Serbian Chetnik Movement (SČP), delivered a speech critical of the government. Opposition political parties demanded that the referendum be postponed until after the first multi-party elections, and called on their supporters to boycott the referendum if the demand was not met.

The state media labelled those opposing the referendum as "anti-Serbian" and "pro-Albanian". The results published by the Republic Electoral Commission (RIK) showed that the referendum passed. On 5 July, the government of Serbia dissolved the Assembly of SAP Kosovo and its government. This was done in response to the proclamation of the Republic of Kosova three days prior. The newly adopted constitution effectively abolished SAP Kosovo's autonomy. "They tried to declare Kosovo a republic and by that they endangered Serbia and Yugoslavia", Sokolović said. This move was condemned by Amnesty International and the European Parliament. The constitution went into effect on 28 September, establishing a semi-presidential system in Serbia. Opposition parties criticised the constitution due to the high amount of powers that were given to the president of Serbia.

Electoral system

With the adoption of a new constitution in September 1990, a new electoral system was introduced in Serbia. The 250 members of the National Assembly of Serbia were elected using a first-past-the-post, two-round voting system from 250 single-member constituencies. All subsequent elections in Serbia have been conducted under a proportional representation system. A constituency's territory could consist of multiple local communities (mesna zajednica), populated places (naseljena mesta), or a single municipality. Eligible voters were able to vote for only one candidate in their respective constituencies. A campaign for an election could have lasted 30 to 90 days.

A candidate could be nominated by one or more political parties or other registered political organisations with at least 100 valid signatures from constituency residents, or by a (grupa građana) instead. A citizens group, under the law enacted in 1990, is a group of 100 citizens bound by an agreement willing to take part in an election. The candidate was submitted to RIK by its proposer. RIK could deny a candidate, after which the deficiencies had to be corrected within 48 hours if the candidate was to be re-submitted again. The symbol of a constituency, the name of the election, and a list of candidates that ran in the constituency were present on the voting ballot. In the first round, a candidate was elected if it earned at least 50% of the popular vote, while in the second round the candidate with the most votes won.

In the presidential election, a candidate had to be a resident of Serbia that was proposed by one or more political parties, political organisations, or a citizens group. A candidate was elected if it received a majority of all votes cast and if at least half of all voters participated in the election. If no candidate received a majority of all votes cast, the second round had to be held within the next fifteen days. In the second round, at least two of the candidates with the highest votes compete. An election was considered valid if the turnout was at least 50%; otherwise, a snap election is scheduled. The newly established position of the president of Serbia was not ceremonial, instead it had significant powers and served as part of the executive branch of the government.

RIK, local election commissions, and polling boards of constituencies have overseen elections in Serbia. At the time of the election, Časlav Ignjatović served as the president of RIK. Parliamentary and presidential elections were called by the president of the National Assembly, who also had to announce their dates. Regarding the 1990 election, the presidential and parliamentary elections were called by Sokolović on 28 September for 9 December. In the event of run-offs, the second round of the parliamentary election was set for 23 December. According to the law, a parliamentary election is held every four years, though it is possible for a snap election to take place. If a snap election occurs, then the president of Serbia has to call the election, as well as dissolve the National Assembly. A presidential election is held every five years.