Turnout was high at many of the 100 polling stations and at some centres hit 30 per cent a few hours after voting opened, according to state-run Kuwait Television.
While Kuwait's two previous elections yielded poor turnout due to an opposition boycott, voters said they were encouraged by more candidates running this time around.
"Their return is needed to strike a political balance in the country. They are more capable of monitoring the government actions," retired voter Ibrahim Al-Tulaihi told AFP at a polling station south of Kuwait City.
"A wise opposition is needed because we don't want more political disputes," Jarrah Mohammad, a government employee, said after casting his ballot.
Unusually for the oil-rich Gulf Arab states, Kuwait has an elected parliament with powers to hold ministers to account, even though senior members of the ruling Al-Sabah family hold all top cabinet posts.
The set-up has led to repeated standoffs between lawmakers and the ruling family and this is the seventh general election in a decade.
The election comes against a backdrop of discontent among Kuwaiti citizens over mounting cutbacks in the cradle-to-grave welfare system they have long enjoyed as a slump in world oil prices hits government revenues.
The emir dissolved the last parliament after MPs called for ministers to be grilled over the cuts to state subsidies.
Islamist candidate Hamad al-Matar, a former MP, said he expects the opposition to win a majority in the 50-seat parliament and prevent the government from raising charges.
"There will be no charges on citizens because we have no problem with finances. We have a problem with government management and corruption," Matar told AFP.
The opposition is fielding 30 candidates among a total of 293 hopefuls who include 14 women.
Women, who have had the right to vote in Kuwait since 2005, were already queueing outside polling stations when voting began at 8 am (local time).
"We want the next parliament to stop the government from hiking prices," said pensioner Maasouma Abdullah.
"We want the government to begin taxing the rich and pay great attention to the low-income sections," added Maha Khorshid, an education ministry employee.
Opposition candidates campaigned heavily for economic and social reform and an end to what they charge is rampant corruption.
The election also comes with Kuwait facing its most acute budget crisis in years. Oil income, which accounts for 95 per cent of government revenues, has nosedived by 60 per cent over the past two years.
And the emirate has fewer alternatives than its Gulf neighbours, partly because of its elected legislature, analysts say.