The first House of Representatives established under the Constitution Act 1852 consisted of 37 members. There were increases until 1881 when the number became 95. After a reduction to 74 in 1891, the present number of 80 (including four Maori seats) was established in 1900. There was periodic reform of the franchise until manhood franchise was established in 1879. In 1893 New Zealand became the first British country to give the vote to women and, with the abolition of plural voting, New Zealand has in this century adopted the principle of one man one vote. The vote is accorded to all British subjects who have resided in New Zealand for 12 months and who have resided for three months in the electorate in which they are to vote. During the nineteenth century there were periods when there were multi-member constituencies, while from 1908 to 1912 there was provision for a second ballot. Now there are single-member constituencies in which the candidate securing the largest number of votes is elected.

The Maoris' communal system of land owning did not enable them to take advantage of the property qualification established in 1852 and, in order to give them effective representation, four separate Maori seats were established in 1867 on the basis of manhood franchise.

The life of Parliament as fixed in 1852 was five years. It was reduced in 1879 to three years, and although there have been four instances – the Parliaments of 1914, 1931, 1938, and 1951 – when this has been extended, the term remains at three years.

The Legislative Council established under the Constitution Act 1852 was an appointive body and in the early stages its upper limit was 15 members. Its size varied over the years – it was as high as 54 in 1885 and 53 in 1950. Until the last decade of the nineteenth century the Council was an influential body which, being conservative in composition, protected the interests of the large landowners. With the advent of a Liberal Government, however, conflict between the Council and the House of Representatives became so intense that the Government successfully reduced the effectiveness of the Council – in particular, by establishing that the Governor was required to accept the Government's advice on appointments and by introducing legislation making the term of appointment seven years. From that time the Council's status decreased until it ceased to perform any very useful function. In 1914 a Legislative Council Act reconstituting the Council was passed, but the Act was not brought into force, and in 1950 the National Government abolished the Council. There was some suggestion that it would be replaced by another body, but although there has been some agitation for a second chamber, including proposals by a select committee of the House of Representatives, there has been little evidence that such a chamber is likely to be established.