The Electoral Commission says voting in advance of the election was at least 20% higher than in the 2008 poll.
More than 2600 polling places across New Zealand were open from 9am - 7pm on Saturday for people to to decide the country's 50th Parliament and to vote in the referendum on the electoral system.
Seventy-seven sites overseas were also prepared for voters.
More than 330,000 people chose to cast their ballot ahead of time.
Chief Electoral Officer Robert Peden says voting early has become increasingly popular.
"They like the convenience of it and it just reflects the changing demands of people's time on Saturdays," he says.
Counting of advance votes was able to take place under secure conditions from 2pm and Mr Peden says that meant the final tally of advance votes should be released by 8.30pm.
Mr Peden said voting appeared to go smoothly with a minimal number of complaints about election billboards being left out after midnight.
Election workers in South Auckland reported a higher voter turnout compared with the last election.
In 2008, nearly 30,000 registered voters stayed at home in the Mangere, Manukau East and Manurewa electorates.
Radio New Zealand's reporter there says this year there was a steady of stream of voters at many of the major polling booths in those electorates.
Some 3,053,705 people, or 93.2% of the eligible population, had registered to vote by 5pm on Friday.
Mr Peden said it was crucial people cast a ballot as they will be voting not only for a government but also on what voting system should be used in the future.
People working past 3pm on Saturday who did not get an opportunity to vote before starting work had to be allowed a reasonable amount of paid time off to vote.
About 19,500 election workers were been employed for the day.