The first sitting of the 50th Parliament was held on 20 December 2011, where members were sworn in and Lockwood Smith was elected Speaker of the House.

The remaining 51 members were elected from party lists using the Sainte-Laguë method to realise proportionality.

The Representation Commission is tasked with reviewing electorate boundaries every five years following each New Zealand census.

[2] The next census was scheduled for 8 March 2011, but it was postponed due to the disruption caused by the 22 February 2011 Christchurch earthquake.

[3] The new date for the census was 5 March 2013,[4] and this allowed enough time to review the electoral boundaries for the 51st New Zealand Parliament prior to the 2014 election.

One hundred and twenty-one MPs were elected to the New Zealand House of Representatives, 70 from single-member electorates, including one overhang seat, and 51 from party lists.

[13] The preliminary results published on election night indicated that the incumbent National Party, led by John Key gained the plurality with 47.99% of the party vote and 60 seats,[10] one seat short of holding a majority.

Preliminary results indicated that ACT New Zealand won less than a third of the party vote it received in 2008, reducing from five seats[15] to one.

Labour leader Phil Goff and deputy Annette King announced on 29 November 2011 that they had tendered their resignations from the party leadership effective 13 December 2011, with both keeping their electorate representations.

[19] The Christchurch Central electorate, where the incumbent Brendon Burns (Labour) and Nicky Wagner (National) had received the same number of votes on election night, was won by Wagner with a majority of 45 votes, with Burns thus out of Parliament, as his list position is not high enough.

[22] However, both electorates were subject to a judicial recount at the request of the Labour and National Parties, respectively, due to the tightness of each result.

[22] As a result of the recount, Nicky Wagner was confirmed as the winner of Christchurch Central with a majority 47 votes on 14 December,[23] while in Waitakere, the recount swung the seat back to Paula Bennett with a majority of nine votes on 17 December.

[25] With the changes in seats for National and the Green Party once the final count was released, this increased to 26 new MPs, with Mathers having joined the newcomers.

[18] The tables below show the members of the 50th Parliament based on preliminary counts of the 2011 general election.

Mojo Mathers, elected as number 14 on the list, is New Zealand's first profoundly deaf MP.

[36] The first sitting of the 50th Parliament was on 20 December 2011, with its main business the swearing in of new members and the election of the speaker.