The New Zealand Police Association was registered on 28 October 1936 and is open to all constables and employees of New Zealand Police.
Membership is voluntary but virtually all who are eligible belong.
The Association was formed after a long struggle by rank and file police through years of poor pay and difficult conditions, which were harshly enforced by their employer.
Originally it was an offence under the Police regulations for Police members to "form a combination" for the purpose of discussing Police business. Despite this, many attempts were made to form a body to work to improve police pay and conditions.
In 1913 a group of Auckland-based police formed a trade union-style organisation based on the model provided by Australian police associations. This organisation provided the basis for the current rules of the Police Association.
Before and during World War One, police joined the PSA. However most left after the Government dropped public service pay (and police pay).
The Labour Government, which took power in November 1935, not only permitted the formation of a Police Association, the then-Police Minister Peter Fraser actively encouraged it. He said the Police needed a body to present the views of the rank and file of the force on improvements to the job.
Since then the Association has worked to improve the pay and conditions of members, to improve the level of service the Police provides to the public and to comment on law and order issues.