The country's most right-wing government is expected to return and bring its first female prime minister to the country since World War II, as well as to Italy on Sunday Sep 25 in an election that is expected to be held on its first female prime minister.
Voting starts at 7 am and will continue until 11 pm when exit polls are published.
It may be many hours before a precise seat count is available due to the complex calculations required by a hybrid proportional first-past electoral law.
A right-wing alliance led by Giorgia Meloni's Brothers of Italy appeared to have a clear victory when the last opinion polls were released two weeks ago.
There is still scope for a surprise with a polls blackout in force in the two weeks before the election.
Support for the left-leaning 5 Star Movement, the biggest party in 2018, has picked up in recent days, according to speculation.
A late surge by 5 Star could damage the rightist alliance's chances of winning a majority in the Senate or upper house, complicating the process of forming a government.
The next government is unlikely to take office before October, with the new parliament not meeting until October 13 if there is a clear cut.
Meloni would be the obvious candidate for prime minister as leader of an alliance that includes Matteo Salvini's LeagueSalvini's League party and Silvio Berlusconi's Forza Italia.
That would cap a remarkable rise for Meloni, a 45-year-old from Rome whose party won only 4 per cent of the vote in the last national election in 2018.
A straight-speaking Roman raised by a single mother in a working-class neighbourhood, Meloni rails against LGBT lobbies woke ideology and the violence of Islam. She has vowed to stop the tens of thousands of migrants who arrive on Italy's shores each year, a position that she shares with Salvini, who is currently on trial for blocking charity rescue ships when he was interior minister in 2019.