Inmates in two prisons will be videoed by cameras fitted on prison officers in a trial for six months, starting this month.
The cameras will be used at high-security units at Rimutaka prison and Auckland maximum security prison as a way of defusing potentially violent behaviour.
Corrections Department chief executive Ray Smith said the cameras will be attached to prison officers' uniforms to record picture and sound.
He said officers will be able to start recording at any time.
Mr Smith said the cameras will mean the actions of prison officers will also be filmed, so lessons can be learned about how volatile situations are best handled.
He said protocols have been developed with the Privacy Commissioner about the use of the cameras, including the destruction of old images.