MPs have been shown footage of potentially violent confrontations in prisons being defused, apparently in part because the prisoner knew they were being filmed.
Auckland and Rimutaka prisons are currently trialling cameras on corrections officers.
Corrections Minister Anne Tolley showed some of the results to Parliament's Law and Order Select Committee on Wednesday.
The footage showed incidents where prisoners were getting agitated before appearing to calm down when they realised they were being filmed.
One of the inmates told a corrections officer he was lucky he was wearing the camera.
Mrs Tolley said the technology could help protect staff and improve behaviour.
"If we can improve the behaviour and the management of prisons, that means we can offer them more opportunities, it keeps our staff safe and it keeps them (prisoners) safe," she said.
Another incident showed how prison officers handled a violent inmate, which the Corrections Department said was good for training.