Reorganisation of the enrolment system caused major problems with the electoral rolls, which left a legacy of unreliable information about voting levels in this election.

Labour had been led by Bill Rowling, who had assumed the post of Prime Minister on the death in office of the popular Norman Kirk.

Labour's Rowling had been criticised by many for inadequately countering Muldoon's confrontational style, and was widely perceived as "weak".

Gradually, as some people wearied of Muldoon's style, Rowling's more reserved manner was held up as an asset rather than a weakness, and Labour began to gain a certain amount of traction again.

Sir Stanley Whitehead MP for Nelson had announced he would retire at the end of the term in 1978, due to ill-health, but he died on 9 January 1976 triggering a by-election instead.

They would work in conjunction with Statistics Department and Electoral Office staff, and at the same time, a switch would be made from a manual to a computerised system.

A report completed in 1979 found that there had been poor liaison between the various departments involved, staff shortages and problems with the computer system.

Together with a northward shift of New Zealand's population, that resulted in five new electorates having to be created in the upper part of the North Island.

In the North Island, fifteen electorates were newly created (Albany, East Cape, Eastern Hutt, Helensville, Horowhenua, Hunua, Kaimai, Matamata, Ōhāriu, Papakura, Papatoetoe, Pencarrow, Rangiriri, Tarawera, and Te Atatū) and six electorates were re-created (Bay of Islands, Kaipara, Taranaki, Waipa, Waitakere, and Waitotara).

The Social Credit Party retained the Rangitikei seat, which it had won in a by-election shortly before the election.