King Mswati III remains popular among many of his subjects
Swaziland is holding its first parliamentary election under a new constitution, amid growing protests calling for more democracy.
Political parties remain banned in the tiny African mountain kingdom, one of the world's last absolute monarchies.
Armed police are guarding polling stations after attempted protests by pro-democracy activists.
A BBC reporter says there has been a good turnout in rural areas, but a poorer turnout in cities.
Several union officials were detained on Thursday as they tried to block the border with South Africa in a move they said was aimed at highlighting the country's problems.
Some Swazis blame King Mswati III for plunging the country into poverty and failing to tackle an Aids epidemic.
The king has been in power since 1986. His government recently organised a lavish $12m (£6.6m) party to celebrate the king's 40th birthday as well as the 40th anniversary of the country's independence from Britain.
For the first time, the polls are being watched by foreign observers from southern Africa.
'Free and fair'
The BBC's Thulani Mtwethwa in the landlocked country says voter apathy was most apparent in Manzini, where there were recent anti-government protests.
Just four people were in line at one Manzini polling station, he said.
The election is the first in Swaziland since an amended constitution was introduced in 2006, allowing for the freedom of association - but keeping a ban on multi-party democracy.
"I am voting because I want my community to improve. We want better health and education," voter Sisana Dlamini told AP news agency in a rural constituency where long lines had formed.
Fifty-five unaffiliated candidates are to be chosen for Swaziland's national assembly.
The king picks a further 10 people for the assembly, which then chooses 10 representatives for the senate, with a further 20 selected by the king.
Electoral official Mzwandile Fakudze told AFP news agency the vote would be "free and fair".
"We have more than six observer missions from different organisations.... We are confident that the process will go on without any disturbances," he was quoted as saying.
Correspondents say the king remains popular with many of his subjects, though opposition has been growing to his lavish lifestyle in a country where most people live in poverty.
Banned political parties, like the People's United Democratic Movement (Pudemo), have dismissed the poll as a sham.
"Pudemo sees this election as a window-dressing exercise trying to pull wool over the eyes of the international community," Pudemo leader Mario Masuku told AFP.