National has enough seats to form a government despite losing a list MP, but will still be smarting after Cabinet minister Paula Bennett lost her Waitakere seat by 11 votes.
John Key said he would be calling a recount of the Waitakere ballot papers.
"It's the party's intention to seek a judicial review. We will file that with the court next week," he said.
Chief electoral officer Robert Peden today released the official results of the November 26 election, taking into account the special votes not counted on election night.
National's share of the party vote fell to 47.31 per cent, down from 47.99 on election night, bumping off list MP Aaron Gilmore and bringing its total number of seats to 59.
With the support of the Act and United Future parties' sole MPs, National still has the numbers to form a Government in the 121-seat Parliament.
It is also likely to sign an agreement with the Maori Party, which met today to discuss a confidence and supply agreement that would also give it the freedom to oppose the Government on certain issues.
But despite National securing the ability to govern, Ms Bennett's narrow loss to Labour's Carmel Sepuloni in the Waitakere electorate will come as a blow to the party.
She remains in Parliament as a list MP, but opponents are likely to use the loss of her seat as a chance to question her credibility.
National still has reason to be buoyed by the results, after an election night dead heat in the Christchurch Central electorate was broken by a 45 vote majority to National's Nicky Wagner.
The win in the traditionally left-leaning seat means one-term Labour MP Brendon Burns will not be returning to Parliament.
Also gone is Labour list MP Raymond Huo, who gets bumped out by Ms Sepuloni's win in Waitakere.
The Green Party's best-ever election result made it the only party to make a gain, with one extra MP bringing their total to 14.
Mojo Mathers will be New Zealand's first profoundly deaf MP, and the fifth in the world.
The Greens got 11.06 per cent of the party vote, up from 10.62 per cent on the night, repeating the party's pattern in recent elections of gains in the special votes.
It has gained an extra MP in four of the last five elections.
In the closely-won Waitakere and Christchurch Central seats, candidates are likely to call for judicial recounts.
They must apply to district courts by Wednesday, with the results of a recount due by the end of next week.
The gains and losses came after 263,469 special votes were taken into account.
Labour got 27.48 per cent of the party vote, up from 27.13 per cent on election night, while New Zealand first got 6.59 per cent, down from 6.81 per cent on the night.
The Maori Party made a modest gain, while Act's 1.07 per cent share of the party vote remained unchanged _ making the party less popular than Mana, which got 1.08 per cent of the party vote, up from 1.00 per cent on the night.
In the referendum, 57.77 per cent of voters chose to keep the MMP electoral system, while 42.23 per cent voted for change.
Voter turnout was 74.21 per cent, down from 79.46 per cent at the 2008 election.
Special votes including overseas votes, out-of-electorate votes and late enrolments accounted for 11.6 per cent of the total.