Israelis are voting in their country's second general election in five months.
Prime Minister Benjamin Netanyahu called the snap election after failing to form a governing coalition with a viable majority after April's vote.
The final opinion polls put his right-wing Likud party neck and neck with its main challenger, the centrist Blue and White party led by former military chief Benny Gantz.
Smaller parties could therefore have a big say in the final outcome.
Negotiations on the formation of a new coalition are expected to start as soon as voting ends at 22:00 (19:00 GMT) and exit polls are published.
The most important things to know about Israel's election
What happened last time?
Likud and Blue and White came away with 35 seats each in the 120-seat Knesset.
Mr Netanyahu declared victory and it appeared that he would be able to secure a majority with the backing of smaller right-ring and religious parties. But after several chaotic weeks the attempted coalition-building collapsed into recriminations.
On the surface was a dispute over Israel's secular versus its religious character, says the BBC's Tom Bateman in Jerusalem.
But ultimately, our correspondent adds, Mr Netanyahu's problems stemmed from a narrowing range of options to build a governing bloc, weakened as he is by the charges of bribery, fraud and breach of trust he faces in three corruption cases, pending a final hearing. He has denied any wrongdoing.
What is Netanyahu's pitch to voters this time?
Throughout the campaign he has made ever more strident appeals to the right wing.
Last week, Mr Netanyahu declared he would "apply Israeli sovereignty" in the Jordan Valley if he won a record fifth term in office. The announcement amounted to a promise to effectively annex 30% of the occupied West Bank, which Palestinians want to be part of a future state.
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Amid international condemnation, the Palestinian leadership called the move a war crime which would bury any prospects for peace.
Mr Netanyahu also reiterated a pledge from the last election to annex Jewish settlements in the West Bank. The settlements are considered illegal under international law, though Israel disputes this.
"We find ourselves at the high point of an historic change in the history of the Jewish people and the State of Israel," Mr Netanyahu wrote in the Maariv newspaper on Monday.
"I am asking now for your confidence in order to complete the historic task and fortify the State of Israel's borders and security forever."
US President Donald Trump's long-awaited plan for a peace agreement between Israelis and Palestinians is expected to be published soon after the election.
What has Benny Gantz promised?
Mr Netanyahu faces an emergent centrist alliance studded with retired generals, who say they will end Israel's increasing divisions. Blue and White was founded in February by Mr Gantz and Yair Lapid, a former finance minister and leader of the Yesh Atid party.
Writing in the Hebrew-language daily newspaper Maariv, Mr Gantz said a victory for Blue and White would "change the dirRead More – Source
