Votes are being counted in Myanmar's first openly contested national election for 25 years.
Turnout is thought to have been 80% - seen as a further big step away from decades of military rule.
Aung San Suu Kyi's National League for Democracy (NLD) is expected to win the most parliamentary seats, although she is barred from the presidency.
The military-backed Union Solidarity Development Party (USDP) has been in power since 2011.
Voting was generally smooth, observers say, with some isolated irregularities.
Crowds of excited supporters appeared outside NLD headquarters in Yangon as darkness fell, apparently expecting the hear results. Instead a party official read out a message urging them to calmly wait at home.
The first official results are expected to be issued from 09:00 local time (15:30 GMT) on Monday.
As polls opened on Sunday, long queues formed at some polling booths, with reports of people waiting from before dawn.
Smiling voters emerged after casting their ballots, some displaying fingers stained with purple - the official sign that they had voted.
"When I cast my vote I was very excited and so worried that I might do something wrong that my hands were shaking," said Kay Khine Soe, in Suu Kyi's Kawhmu constituency.
Voting in Yangon, Wuhan Datong said: "I am 57 years old. I never participated in the previous voting since I had doubts over it. But the election this time is fair. So I have come to vote."
About 30 million people were eligible to vote in the election in Myanmar, also known as Burma.
More than 6,000 candidates from over 90 parties vied to be elected to the 664-seat parliament in the first national elections since a nominally civilian government took power in 2011.
However, 25% of seats are reserved for unelected military representatives, who are expected to side with the USDP.
Suu Kyi, a former Nobel Peace Prize laureate, is barred from the presidency as the constitution disqualifies anyone with foreign offspring - her children are British.
The NLD must take 67% of all contested seats in order to gain a majority.
On Thursday, she said she would be "above the president" if her party won.
Current President Thein Sein said he would accept the election result. He cast his ballot at a school in the capital, Nay Pyi Taw, built in 2005 by the military.
Hundreds of thousands of people - including minority Rohingya Musli- were denied voting rights, raising concerns about the fairness of the poll.
The BBC's Jonah Fisher in Yangon says there are no reliable opinion polls in the country, so no-one really knows how the vote is going to play out.
Ahead of the vote, security was stepped up across the country, with some 40,000 police guarding polling stations.
Ruled by the junta for nearly half a century, Myanmar has seen economic and political reform in recent years.
Suu Kyi has already raised concerns about poll fraud and voting irregularities. In the 1990 election, the NLD won a majority, but the results were largely ignored by the generals.
For its part, the government has warned that rapid change could lead to civil unrest.