The last votes have been cast in a remote Northern Territory electorate's by-election, called after the member for Arafura died suddenly at the end of last year.

There's been a tough two-week schedule for electoral officers, who went to 22 remote communities before finishing in Jabiru, near Kakadu National Park.

The NT Electoral Commission's mobile polling team used four-wheel-drive vehicles and helicopters to get to remote towns, communities and outstations across the 57,000 square kilometre-sized electorate.

But by Thursday evening, with only two days to go, only 50 per cent had cast their vote.

The NTEC said it had placed a special focus on increasing voting services in towns like Maningrida, which had a voter turnout of just under 30 per cent last time.

As a sparsely populated yet densely diverse electorate, candidates face a lot of challenges, said Dr Nathan Franklin, a political sciences lecturer at Charles Darwin University.

"It's got Arnhem Land, it's got Kakadu, it's got the Tiwi Islands ... the only kind of defining similarity across the region of this electorate is football."

Dr Franklin said essential services like health access, education and housing were at the front of peoples' minds - "basic stuff that people in big cities take for granted."

The by-election comes after the sudden passing of the Labor member for Arafura last December, described by Chief Minister Natasha Fyles as "beloved" and "well respected."

The member, whose name and image is not being used for cultural reasons, was from the Tiwi Islands and served in parliament for more than six years.

Labor's Manuel Brown will hope to continue the legacy of his former boss if he wins against Country Liberal Party (CLP) candidate Leslie Tungatalum and Federation Party candidate Alan Middleton.

"Improving roads, housing and health outcomes for the constituents of Arafura will be my biggest priorities," he said via email.

He also said he would make sure highly anticipated road and bridge upgrades on the Tiwi Islands would be quick and efficient.

Both Mr Brown and Mr Tungutalum have roots in the Tiwi Islands, though Mr Brown currently lives in Arnhem Land, where he previously worked with the Northern Land Council.

Mr Tungutalum, running for the CLP, is the deputy mayor of the Tiwi Islands Regional Council, and the son of the first Indigenous politician to be elected to NT parliament.

Gunbalunya-based Federation Party candidate Mr Middleton, who was able to fly himself out to accompany the campaign and voting schedule, also said infrastructure upgrades would be key.

However, he said his main priority would be to increase transparency and community involvement.

The electorate was first created in 1983, with boundaries redrawn prior to the 2020 election to include the area surrounding Kakadu National Park.

Historically, the electorate has always voted Labor, with the exception of one CLP candidate who was elected from 2016 to 2020.

Labor currently hold a majority in NT parliament.

The NTEC is expected to announce preliminary results Saturday night.