After polling closed, chief election commissioner Dinesh Thapalia said 61 per cent of the country's 18 million eligible voters had cast their ballots, according to preliminary estimates, down from the 68 per cent seen at the last election in 2017.
"It is less than our expectations," he said.
One person was killed in a clash during the voting, which was largely peaceful, Thapalia added.
Vote-counting in many places will start late on Sunday, the Election Commission said. It could take up to two weeks to declare final results.
There were no pre-election polls, though political analysts expect the ruling alliance of the Nepali Congress and some former Maoist rebels to retain power.
Political stability has proven elusive for the poor nation, wedged between China and India, discouraging many investors. Nepal has had 10 governments since the abolition of a 239-year-old monarchy in 2008.
A new government will face the challenge of reviving the economy and curbing high prices at a time of fears that a global recession might reduce remittances, which account for about a quarter of gross domestic product (GDP).
Tourism, which contributed 4 per cent to GDP before the pandemic, has yet to fully recover. In the first 10 months of this year, roughly 450,000 tourists visited Nepal, less than half the number seen in the whole of 2019, before the Covid pandemic.
Foreign reserves are shrinking and the retail inflation rate has been hovering at six-year highs of about 8 per cent in the Himalayan nation, where one in five people live on less than $2 a day.
"We need political stability for faster growth of the economy and a government that can guarantee security to investors," said Prakash Thapa, 25, another voter in the Phaimlamchuli suburb.
Nepal's 275-member parliament and the 550 members of seven provincial assemblies are elected through a mix of first-past-the-post and proportional representation systems.