Queenslanders are deciding who will become premier after a rollercoaster four-week campaign.

Premier Steven Miles and Liberal National Party leader David Crisafulli cast their votes on Saturday morning and face a nervous wait after the race to govern tightened in the final days of campaigning.

Mr Crisafulli was tipped to end the Labor government's nine-year reign after dominating polling early.

(David Crisafulli and wife Tegan cast their votes, as do Steven Miles and wife Kim. (Jono Searle/AAP PHOTOS)

But Mr Miles has made ground after a final campaign blitz, indicating the election race might have a photo finish.

In Brisbane on Saturday, Mr Miles and his wife Kim cast their votes at Kallangur State School while Mr Crisafulli and his wife Tegan voted at Springwood State High School.

Mr Crisafulli told reporters he was getting around the booths to thank his party's volunteers and to spread the message that Queenslanders "deserve better than what you're getting". 

Mr Miles said he wanted to win a term in his own right after taking over from Annastacia Palaszczuk after she resigned in late 2023.

He wanted a chance to deliver on the promises he had made to Queenslanders, the premier told reporters on Saturday. 

(Opposition Leader David Crisafulli made a last-minute pitch to voters on Saturday morning. (Jono Searle/AAP PHOTOS)

Nearly half of Queensland's voters have already made up their minds, casting their ballot early.

The remainder will enjoy a democracy sausage on Saturday, with Labor hoping to secure a fourth-straight term.

The LNP is aiming to form its first government since Campbell Newman's 2012-2015 stint.

Labor has governed Queensland for 30 of the past 35 years.

"Being the state's premier these last 10 months is the greatest honour of my life," Mr Miles has said.

"I have endeavoured to ... make sure every single one of those minutes count."

He made the most of his last days on the campaign trail, visiting 36 seats in 36 hours.

(Premier Steven Miles cast his vote after a blitz on dozens of seats in the campaign's final days. (Darren England/AAP PHOTOS)

Both leaders have campaigned hard on key election issues youth crime, housing, health and cost-of-living pressures.

But abortion emerged as a major talking point in the past fortnight after a crossbencher vowed to repeal the legislation if elected.

Abortion was decriminalised in Queensland in 2018.

Mr Crisafulli has been under enormous pressure in the past two weeks, repeatedly refusing to explain how he would guarantee abortion laws would not change.

It has coincided with LNP's dip in the polls.

The latest Newspoll conducted for The Australian newspaper showed Mr Miles rated as a better premier at 45 per cent compared to 42 per cent for Mr Crisafulli.

But the LNP remained ahead on a two-party preferred basis at 52 to Labor's 47 per cent.

The LNP did not reveal its costings until Thursday, including changes that would save almost $7 billion on consultancies and contractors.

(A voter and a non-voter make their way through a corridor of election posters in Brisbane. (Darren England/AAP PHOTOS)

Labor claimed it meant the LNP would cut public service jobs to keep the budget in the black.

Mr Crisafulli said Labor's nine years in power had led to a lack of government accountability or transparency.

"It's getting worse and for the sake of this great state, Queenslanders have to vote for change," he said.

Robbie Katter, the leader of Katter's Australian Party, which has four MPs and is fielding 11 candidates, told the Nine Network he was open to doing a deal with the LNP and his party could become a powerbroker.

"It's a really good opportunity for the LNP to grab hold and partner with a party that can really turn the tide on things," he said on Saturday.

On the abortion issue, Mr Katter said that would be tested in parliament.

"It wasn't our priority, but we've pushed on it and we'll stand up for what we believe in."

Labor has 51 seats and the LNP 35.

A party needs 47 seats for majority government.

By Savannah Meacham and Fraser Barton in Brisbane