Candidates from 20 lists of political parties and coalitions are running in the election for a 250-seat parliament.
On Sunday, 8,383 polling stations in Serbia and 57 abroad will be opened until 2000 hrs.
According to the latest opinion polls, parties that have the best chances of winning seats are the Serb Radical Party led by ICTY indictee Vojislav Seselj, the Democratic Party led by the incumbent Serbian President Boris Tadic and the coalition of Prime Minister Vojislav Kostunica's Democratic Party of Serbia and the New Serbia party.
Other lists that may pass the five percent threshold are the G17 Plus and the coalition of the Liberal-Democratic Party led by Cedomir Jovanovic, the Citizens' Alliance led by Natasa Micic, the Social Democratic Union led by Zarko Korac and Social Democratic League of Vojvodina led by Nenad Canak.
The Socialist Party of Serbia of the late Serbian president Slobodan Milosevic, who died in March 2006 during his trial before the UN war crimes tribunal, stands a slim chance of entering the parliament, according to the surveys.
For these elections, six parties representing minorities nominate their lists: the Alliance of Vojvodina Hungarians, the Union of Serbian Romany, the Hungarian Harmony list, the Romany Party, the coalition for Sandzak representing local Bosniaks (Muslims) and the coalition of ethnic Albanians in the Presevo valley representing Albanians in the south of Serbia who have boycotted Serbian elections for ten year.
Ethnic Croat representatives are candidates on the list of the DS party led by President Tadic.
Officials of international organisations including OSCE, the Council of Europe, the European Union and diplomats from the Russian Federation, the United States, Great Britain and Slovakia as well as representatives of nongovernmental organisations are to monitor the course of the voting.
A ban on electioneering before the elections took effect on Thursday at midnight and lasts until 2000 hrs Sunday with the closing of the polling stations.
First unofficial results are expected to be published by the CeSID (Centre for Free Elections and Democracy) nongovernmental organisation at about 2200 hrs Sunday.
The state commission is to release the final official results until 25 Thursday.
The last two days before the elections were marked by several incidents.
One of them involved threats to opposition politician Cedomir Jovanovic.
Another incident happened in a village populated by ethnic Roma near the town of Leskovac where posters with swastikas and graffiti with offensive messages appeared on houses, the Radio B92 reported.
Local police removed the posters and are searching for perpetrators.