Some 6.5 million voters are choosing the president, a new parliament and local authorities in the capital, Belgrade, and over a dozen other towns and municipalities.
Voters in Serbia cast ballots in a triple election likely to keep in power a populist government in the Balkan country that has refused to impose sanctions on Russia over its operation in Ukraine.
Opinion surveys ahead of the vote on Sunday have predicted that President Aleksandar Vucic will win another five-year term and that his right-wing Serbian Progressive Party will yet again dominate the 250-member assembly.
But opposition groups stand a chance to win the majority in Belgrade, analysts say. This would deal a serious blow to the populists' decade-old unchallenged rule in Serbia.
Vucic, a former ultranationalist who has boasted of close ties with Russian President Vladimir Putin, has sought to portray himself as a guarantor of stability amid the turmoil raging in Europe.
Though Serbia is formally seeking European Union entry, Vucic has fostered close ties with Russia and China, counting on the Serbs' resentment of the West over the NATO air war.
Serbia has supported a UN resolution that condemned Russia's attacks on Ukraine, but Belgrade has not joined the sanctions against Moscow.
Beleaguered opposition groups have also mostly refrained from publicly advocating a tougher line on Moscow. Russia has supported Serbia's claim on Kosovo, a former province that declared Western-backed independence in 2008.
Concerns over Vucic's domination
After boycotting the previous vote in 2020, main opposition parties have said this vote is also far from free and fair because of Vucic's domination over the mainstream media and the state institutions.
Vucic’s main opponent in the presidential election comes from a centrist-conservative coalition, United for Victory of Serbia, which comprises the main opposition parties.
General Zdravko Ponos, a Western-educated former army chief of staff, is hoping to push Vucic into a second round in the presidential ballot.
In the run-up to the vote, reports have emerged of ballots being sent to addresses for people who don't live there, prompting opposition warnings of potential fraud.
Since his party came to power in 2012, Vucic has served as defence minister, prime minister and president.