A handful of voters were already queuing up as stations opened at 0500 GMT, waiting to mark their ballots
in blue voting booths, though many Israelis were taking advantage of the election day public holiday to sleep in.
Netanyahu was out early, casting his ballot with his wife Sara and their two sons at a polling station in the upscale Rehavia neighbourhood of Jerusalem, where the prime minister's official residence is located.
The prime minister, after casting his ballot said he hoped for "a flood of votes" for his rightwing joint Likud-Beitenu bloc, Israeli media reported.
Also among those out early in the unseasonably warm weather was Joe Jamal, 55, voting in the central Jerusalem neighbourhood of Katamon.
"I don't expect much change. I'm still hoping for an alternative, a move to the centre, for which I'm voting," Jamal, a doctor, told AFP.
His expectations track polling ahead of the vote, which has consistently projected an easy win for the joint list of Netanyahu's Likud faction and the secular nationalist Yisrael Beitenu of former foreign minister Avigdor Lieberman.
The prime minister is expected to preside over a sharply rightwing government that is considered less likely to achieve a comprehensive peace deal with the Palestinians and could increase Israel's diplomatic isolation.
The government will face key diplomatic and foreign policy questions, including Iran's nuclear programme, which much of the world believes masks a weapons drive, and a Middle East profoundly changed by the Arab uprisings.
But domestic challenges will be no less pressing, with a major budget crisis and austerity cuts on the horizon, even as Israelis express widespread discontent over spiralling prices.
The joint Likud-Beitenu list may be confident of leading those competing for the Knesset's 120 seats, but polls show that the two parties will lose around 10 of the seats they hold now, garnering around 32 seats in total.
The centre-left Labour party is projected to trail in second place with around 17 seats. Its chief, Shelly Yachimovich, is expected to become leader of the opposition after pledging she would not join a Netanyahu government.
The campaign's big surprise has been Naftali Bennett, the young, charismatic new leader of the hardline national religious Jewish Home. He took over the party in November and has quickly become a rising star among settlers.
The party, which firmly opposes a Palestinian state and won just three seats in 2009, is on course to win 15, making it the third faction in parliament and a likely partner in any future coalition government.
Bennett's success has rattled Netanyahu, pundits say, with the premier pushing to stem the defection of voters to Jewish Home by burnishing his own credentials as a defender of Israeli settlement in the occupied territories.
Overall, according to final polls, the rightwing-religious bloc will take between 61 and 67 seats, compared with 53 to 57 for the centre-left and Arab parties.
Some 5.65 million Israelis are eligible to vote in Tuesday's parliamentary elections, including Arab citizens of the Jewish state, who are expected to stay away from the polls in record numbers.
Voters will be able to cast ballots at 10,132 polling stations, which are open for 15 hours, with television exit polls due to be broadcast immediately after they close.
Security has been tightened across the country and more than 20,000 police officers have been deployed to secure the vote.